A

Address bus - Data bus used by the CPU to carry data that identifies the memory locations where the data bits are being sent to or retrieved from.

Alpha - RISC processor manufactured by DEC.

Apache - The HTTP server program.

Applications - Programs that are used to access and manipulate and interact with documents and resources interactively at the users command, rather than directly with specific resources

Application Layer - OSI layer in charge of program-to-program communication.

Apt-get - The standard Debian package manager, not to be confused with dpkg, the standard Debian installer and configuration tool

Architecture - The type of processor in a computer. Also, the type of processor a program was compiled to run on.

ARM - RISC type processor used in embedded devices

Artistic License - The Artistic License is a license that gives the author control on what changes can be made to the files while still remaining open source.

Aterm - Another terminal emulator.

Automake - GNU tool for generating makefile.in files

B

Bandwidth - The difference between the highest and lowest frequency available for transmission in a communications system.

Bash - Bourne again shell. A derivative of the Bourne shell.

/bin - Directory where essential programs are stored

Binaries - Code written in machine language and is able to be processed by the microprocessor. Compiled code, however, may also be an object file, though it contains machine code, cannot run on its own but helps extend other machine code.

BIND - Common server used to provide Domain Name Services.

BIOS - Basic Input/Output System (BIOS).The BIOS contains the code required to control the display screen, disk drives, keyboard, serial communications, and a number of miscellaneous functions. The BIOS makes it possible for a computer to boot itself.

Boot disk - Disk used to load the kernel of an operating system

Bridge - A device that connects two LANs or two segments of the same LAN, even if they are different types of networks or use different protocols. Bridges work at the Data Link Layer of the OSI model and work with MAC addresses.

Broadcasting - To send the same transmission to everyone on a network.

BSD License - The BSD license requires a copyright notice and in the past required that credit be given. The BSD license does not require distribution or redistribution of the original or modified code.

Bus - An assortment of wires or circuit paths through which data is transmitted from one part of a computer to another.

C

C - A programming language closely associated with Linux

C++ - An object oriented programming language closely associated with Linux

C library - Collection of core C language functions compiled in one block of machine code.

Central Processing Unit (CPU) - A CPU, sometimes referred to as a processor or microprocessor, is a microchip about the size of a thumbnail that acts as a computer's brain. Common examples of CPUs include Intel's Pentium and 486DX.

chgrp - Changes the group that owns the file.

chmod - Command used to change the permissions

chown - Changes the owner or group assigned to a file.

CLI - Command Line Interface

Clients - Programs that request services provided by a server (Daemon)

Closed Source - Closed source software is proprietary or software for which source code is not available.

Command mode - The mode that a user will select in vi by using the esc key. This mode allows users to run commands such as q for quit or w for writing the file.

Command prompt - A line in a terminal that signals the shell is ready to accept commands.

Computer - An electronic device created to enable users to input, manipulate, store, and output information.

Configuration - This term refers to the way that a computer's operating system is set up or the variety of components that make up a system. The term can refer to either hardware or software, or a combination of both. In some instances, configuration is accomplished by setting switches and jumpers.

Connection-oriented - Connection-oriented TCP/IP protocols establish that the sender and receiver are both ready to communicate and ensure that reliable error-free data transfer occurs.

Connectionless - Connectionless TCP/IP protocols simply send packets to a receivers address but do not ensure that the receiver is actually listening or that the data is being delivered reliably.

Core dump - A recording of the memory contents of an program that crashed

Cron - A daemon that executes commands depending on the minute, the hour, the day of the month, the month, the day of the week, which user is running the command, what command to run

crontab - The file where the cron jobs are stored.

csh - C shell, an alternative to bash.

Cups - Common Unix Printing System

D

Daemons - Programs that listen to connections from other computers or software.

Data - In the world of computers, data refers to any information that goes into or is taken from the computer.

Data frames - Protocol that handles data in special packets.

Dead tree version - Printed version. You can't grep dead trees.

.deb - Debian package, a tarball with additional Debian packaging files

Debian - Distribution of GNU/Linux, which uses a snapshot release cycle

Desktop environment - Panels, application launchers, icons, panel menus and behavior features combined into a consistent look and feel

DHCP - Acronym meaning Dynamic Host Configuration Protocol. DHCP is a TCP/IP protocol which automatically assigns a temporary IP address to a network host.

Direct Memory Access (DMA) - Means by which data moves between a system device, such as a disk drive, and system memory without direct CPU control. DMA frees up the CPU for other tasks.

Distro - Slang expression for the word distribution, or a type of Linux

DNS - Domain Name System

Domain Name System (DNS) - The domain name system (DNS) is the way that Internet domain names are located and translated into IP (Internet Protocol) addresses.

dpi - Dots per inch

Dump - A program that does backups on filesystems rather than file or directory

E

Echo - The echo command writes the text given to it to standard output

Emacs - One of the two main text editors for Linux, the other being vi.

Encryption - Conversion of data into a secret code for transmitting over a public network. Prevents unauthorized users from accessing the data.

Environmental variable - Holds values that give information to the applications as defaults.

Eterm - The enlightenment terminal emulator.

Ethernet - Ethernet is the most widely-installed LAN technology. Specified in the IEEE 802.3 standard, Ethernet was developed by Xerox, DEC and Intel.

EULA - End-User License Agreement

Execute permission - Permission to load a program into memory to be executed, as opposed to simply reading it.

ext2 - The second extended filesystem

ext3 - The third extended filesystem, that is actually ext2 with journaling support

F

Fault tolerance - A system’s ability to recover from a variety of hardware failures including CPU failure, power supply failure and hard drive failure. A properly configured fault-tolerant system will loose no data and suffer minimal down time after a failure. Fault tolerance can also be described as the elimination of a single point of failure.

fdisk - Program to create partitions

File manager - Program that gives users access to files to change them, move them, copy, delete, and view them in a comfortable interface

Firewall - A combination of hardware/software designed to prevent unauthorized access to or from a private network. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.

FQDN - Fully Qualified Domain Name

Frame - A frame is data that is transmitted between network points as a unit complete with addressing and necessary protocol control information. The use of frames depends on the network and protocol.

Freeware - Freeware is also copyrighted, it is available for free. Usually, no modifications are allowed to the copyright notice or the program.

fsck - Filesystem check program. It can do some repairs and recovery on hard disks

FTP - File Transfer Protocol. Procedure to download files from or upload files to remote computer systems.

FTP server - Program that offers file access over the file transfer protocol

G

GCC - GNU Compiler Collection

Getty - A daemon that handles the login process

GID - Group ID number

GNOME - Desktop environment (GNU Network Object Model Environment)

GNU/Linux - GNU is a registered trademark of the FSF. Linux is a registered trademark of Linus Torvalds. The GNU Project wrote the operating system and tools. Linus Torvalds providing the missing piece, the kernel

GPL - GNU General Public License. This license is used by free software developers.

groupadd - Adds groups to the system

GRUB - GRand Unified Bootloader.

GUI - Graphical User Interface

H

Horizontal sync - The lines per second the monitor is able to update.

Host - In Internet protocol specifications, the term host means any computer that has full two-way access to other computers on the Internet. In this context, a host is a node in a network. A host can also be the company or Web server that provides Web services, which is known as hosting. In other contexts, the term host generally means a device or program that provides services to some less capable device or program.

HTTP (HyperText Transfer Protocol) - HTTP is widely used to transfer information from Web servers to Web browsers.

Hub - A common connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports. When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets. Hubs operate at the Physical Layer of the OSI Reference Model.

I

ifconfig - Configures the network interface

Input devices - A device used for putting data into a computer.

Insert mode - This mode is used when users want to type within vi, obtained by selecting the "i" key

insmod - The insmod command followed by the driver name followed by options in the form option=value will configure devices to the user's choice of settings.

International Standards Organization (ISO) - ISO, founded in 1946, developed the OSI reference model (among many other standards) that has allowed companies to create compatible technologies.

Internet Assigned Numbers Authority (IANA) - Part of the Internet Architecture Board. Registers and controls the assignment of various Internet destinations.

Internet Protocol (IP) - A connectionless TCP/IP protocol used to route packets across the Internet. The most widely used version of IP today is Internet Protocol Version 4 (IPv4). IP Version 6 (IPv6) is the upcoming version.

IP Multicast - Internet Protocol multicasting. Extends multicasting technology to a TCP/IP network.

IRQ - Another term used for a hardware interrupt or and interrupt request channel.

J

Journaling - The process of keeping a record of operations that were requested to occur on a disk or other storage area.

K

KDE - K Desktop Environment

kerberos - Authentication server

kernel - Regarded as the heart of the operating system, the kernel interprets user input and coordinates with the computer's software and hardware components to complete the user's requests.

konsole - KDE console program.

ksh - Korn SHell, an alternative to bash

L

Legacy - Describe older versions of still current devices. An ATA-1 is an ATA family legacy drive.

LaTeX - LaTeX is a structured text arrangement and typesetting applications

Layered - Refers to one or more levels of routines and protocols lying between the application and the computing hardware. Layering makes it easier to adapt programs to different types of equipment.

LCD - Monitor type that uses a polarized, molecular structure liquid, held between two see-through electrodes, as its display medium.

LDAP - Lightweight Directory Access Protocol

Libraries - A collection of commonly used functions compiled in one block of machine code.

LILO - LInux LOader. A boot loader.

Linus Torvalds - Finnish programmer who created the Linux kernel

Local Area Networks (LAN) - A collection of computers and other devices within a physical computer network providing the building blocks for MANs and WANs.

Log files - Files that contain a record of activities that occur when a program is running.

lpd - Line printer spooler daemon

ls - Used to list the items in the directory

M

Make program - Builds complex documents and binary files from source

Man - Manual pages. These are accessed by typing man and the desired page. For example, the manual page for vi would be opened by typing man vi.

MAC address - The Media Access Control (MAC) address (or physical address) is a network device's unique hardware number. On an Ethernet LAN, it's the same as the Ethernet address. In contrast, an IP address is referred to as a logical address.

Media Access Control (MAC) - One of the Data Link Layer's sublayers. The other one is LLC, Logical Link Control.

Memory cache - A memory cache, also known as a CPU cache, is a memory bank that links the CPU and main memory. The CPU cache uses SRAM (static RAM) to temporarily store data and instructions the CPU needs to execute commands and programs.

mkfs - Formats filesystems and partitions

Microkernel - Contains enough components to start a computer and prepare resources. Everything else communicates to the kernel using message passing functions rather than calling kernel functions. Extremely modular. Drivers run in user space than kernel space.

MIME (Multipurpose Internet Mail Extensions) - MIME converts binary data into text for transmission through e-mail. MIME is one of many converters available, but MIME is the most popular.

MIPS - Processor used with game systems, digital cameras, and SGI workstations.

mkdir - Used to create directories

modinfo - The modinfo command followed by the driver name will show all the available options for that driver. Once the user knows the options the options can be given to the insmod command.

modprobe - Loads driver modules into the kernel

Module support - building the kernel to allow drivers to be inserted or removed separately from the kernel

Monolithic - The idea to build an application or program with everything built into one binary or into just a few binaries, usually used to describe kernels

Mount points - Place where a filesystem can be inserted into the directory tree

Multicasting - Transmission of a message to a select group via email, teleconferencing or videoconferencing. In networking, a distinction is made between broadcasting and multicasting. Broadcasting sends a message to everyone on the network whereas multicasting sends a message to a select list of recipients.

mv - Used to move files

N

NetBEUI - Enhanced version of the NetBIOS protocol used by various network operating systems. Originally developed by IBM, NetBEUI has been adopted and extended by Microsoft and Novell.

NetBIOS - Networking protocol in DOS and Windows networks that acts as a programming interface for applications at the Session layer.

Netmask - Defines the IP addresses visible from a certain device so that the kernel knows to which network device to send packets.

netstat - A program that finds the open connections

Network Address Translation (NAT) - Specified in RFC 1631, NAT lets a LAN use one set of IP addresses for internal traffic and another set of addresses for external traffic.

Networking topology - In the context of communication networks, a topology describes (pictorially) the configuration or arrangement of a network, including its nodes and connecting lines. Topologies, in general, refer to a physical layout, but the term logical topology also is used.

NFS - Network Filesystem Protocol

NIC - Network Interface Card. An expansion board that allows a computer to be connected to a network.

Node - Any network-connected device that can communicate with other network devices.

nslookup - Used to translate from the IP address to the domain name address

O

Open Source - Open source software is software that makes the code available. The licenses associated with open source allow users to modify, edit and redistribute the code and applications/tools or utilities.

Open Systems Interconnection (OSI) - An ISO standard for international computer communications. Sets up a structured framework of protocols in seven layers.

Operating system - Collection of programs that represents the functions and features the kernel provides, as well as management features useful to users.

Output devices - Any internal or peripheral device attached to the system unit either internal or peripheral that completes the task the CPU intends it to do.

P

Packets - A packet is data that is transmitted between network points as a unit complete with addressing and necessary protocol control information. The use of packets depends on the network and protocol.

Parallel - The ability to transfer data multiple bits a time rather than 1 bit at a time as on serial processing.

Parity Checking - Technique used to detect errors. It uses character bit patterns that are forced into parity. This is accomplished by the addition of a one or zero bit to each byte, as the byte is transmitted; at the other end of the transmission, the receiving device verifies the parity and the accuracy of the transmission.

Partitioning - Dividing the hard drive space into different sections

Passwords - A code usually compromised of keyboard characters (numbers, letters, and special characters) used as an electronic “key” to access various resources.

Password Policies - Rules and protocols governing access to computer and network files.

Password protection - Coded protection of a system, object, or other resources through the use of a password.

Patches - Used to automate updating of text files

Path Environment Variable - Tells the shell where to look to find binaries

PCI - Peripheral Component Interconnect. Adapter standard for communicating between adapters and the rest of the computer.

PCMCIA - Personal Computer Memory Card International Association (PCMCIA), is an international standards body and trade association. PCMCIA was created in 1989 to establish standards for connecting peripheral devices to portable computers. It is now consists of more than 500 companies.

PDF - Portable Document Format.

Perl - Practical extraction and report (or Perfectly Eclectic Rubbish Lister) language developed by Larry Wall

PHP - PHP is a scripting language that is primarily used to generate HTML.

Physical Layer - OSI's first layer, managing data entry and exit from the network media.

PING - Verifies a connection between two nodes on a network

Plug and Play - Term used to refer to the ability of a computer system to automatically configure expansion boards and other devices. It is designed to eliminate setting DIP switches, jumpers, and other configuration elements.

Port - An opening that allows network data to pass through. Physical ports or those physically connected to a device with a cable or some other type of hardware. Logical ports are electronic ports used by devices to transmit or receive data (e.g., default port 80 used for the transmission of Web data).

Portability - The extent it is possible to port an application from one architecture or platform to another without changing the code much. C is very portable. Visual Basic is not as portable.

POST (Power On Self Test) - The diagnostic testing sequence that a computer's basic input/output system runs at startup to determine if the keyboard, random access memory, disk drives, and other basic hardware are working correctly.

PowerPC - RISC type processor used with Power Macs and the Gamecube.

Presentation Layer - OSI's sixth layer, managing data representation conversions.

/proc - Virtual filesystem used to access kernel variables and structures

Process id (PID) - Numbers that identify the process on the system

Proprietary - Proprietary means not open or free source. Proprietary is owned exclusively.

Protocols - Agreed upon procedures and formats for transmitting data between devices.

Protocol stack - A set of protocol layers that work together on different levels to enable data communication.

Python - An object-oriented programming language.

Q

R

RAM (Random Access Memory) - A group of memory chips functioning as the computer's primary workspace.

Read permission - Permission to read the file.

Recompile - To rebuild the binary file from source

ReiserFS - Journaling filesystem that stores many small files in one block to increase performance and save space

Relaying - Passing or forwarding email from one server to another, with usually the last server being the destination.

Remote access - Requesting services from a remote device or computer.

Remote-Access Environments - Settings that pertain to a client accessing a server or network from a remote location.

Remote shells - A remote access daemon.

rhosts - File containing the trusted hosts.

Richard Stallman - Founder of the GNU Project and Free Software Foundation

rlogin - Allows remote login without a password based on trusted hosts lists.

.rpm packages - Red Hat package, a tarball with additional Red Hat packaging files

rm - Used to remove or delete items

rmdir - Used to remove directories

Root - The admin account or superuser

root directory - / The directory under which every part of Linux is organized

Router - Device that connects LANs and determines where packets go. Functions at the Network Layer of the OSI model and works with IP addresses.

RPM - Package format used by the Red Hat Package Manager

rsh- Remote shell

Runlevel - Number that identifies the current operating mode of the system

S

Security Patches - Updates applied to a system to correct and improve existing security flaws.

set - The set command sets the environment variable

setgid - Runs the program with the access privileges of the group that owns the program, rather than the group that is running the program.

setuid - Runs the program with the access privileges of the user that owns the program, rather than the user that is running the program.

Serial port - Port commonly used for old mice, old printers, external modems, null modem networking and console debugging

Session Layer - OSI's fifth layer, establishing and maintaining communications channels.

sh - Bourne Shell. Created by Steve Bourne

Shadow password - Passwords are hashed and stored in a separate file from the rest of the user information, creating a much more secure environment since passwords are not stored as plaintext on the machine.

Shareware - Shareware is copyrighted but often offered as incentive to further purchase the software.

Shell - The user program that receives input and passes commands to the kernel.

Shell script - Used for running sets of commands together.

Small Computer System Interface (SCSI) - SCSI uses a 50-pin connector and allows up to eight devices to be connected in a daisy-chain. The original 1986 SCSI version is sometimes called SCSI-1 to differentiate it from the 1994 SCSI-2 and more recent versions.

Source code - Code in the programming language, not yet compiled.

Spam - UCE, unsolicited commercial email

SPARC - RISC type processor from Sun – a microprocessor.

Spool directories - Store files waiting to be printed

SPX(Sequenced Packet Exchange) - SPX is the protocol for handling packet sequencing in a Novell NetWare network. SPX prepares the sequence of packets that a message is divided into and manages the reassembly of received packets, confirming that all have been received and requesting retransmission when they haven't.

SQL - Language used mostly with databases

SRPMS - Package format used for source code

SSI - Server Side Includes

Subnet mask (also known as a network mask) - The number used by TCP/IP network devices to identify the Network ID and Host ID portions of an IP address.

Syslogd - A service that listens to requests from applications to log activity to a log file

T

Tar.bz2 - Tar file compressed with the bzip2 program

Tar file - Tape archive, the format stored on backup tapes, often used to collect files into one file together

Tar.gz - Tar file compressed with the gzip program

TCP (Transmission Control Protocol) - TCP transfers information between two devices on a TCP/IP network. TCP also monitors information transmission. It is a connection-oriented protocol.

Telecommuting - Working at a remote location using a computer connected to the company network.

Text editor - A program that edits text, but does not provide formatting, etc., commonly present in word processors.

TLDP - The Linux Documentation Project. A good resource of documentation. The website is www.tldp.org

traceroute - Traces the route of a data packet from one IP address to another

Transmission Control Protocol (TCP) - Transfers information between two devices on a TCP/IP network. Unlike IP, TCP is a connection-oriented protocol.

Transport Layer - OSI's fourth layer, responsible for data transmission integrity.

U

UDP(User Datagram Protocol) - UDP does not route data to a specific host; it simply broadcasts data. It is a connectionless TCP/IP suite protocol.

Uid - User ID number.

Umask value - Value that represents the default permissions when a file is created.

Universal Serial Bus (USB) - An external bus standard.

Username - A unique name assigned to a person for identification purposes and access to resources. The username usually is accompanied by a password.

Users - The people who have accounts on the system.

User and Group Permissions - User and Group permissions pertain to the permissions placed on objects (files, drives, printers, etc.). These permissions usually allow full, partial or no access to the object.

user interface - Combination of a server, shell, a set of framework libraries and an environment. The user interface allows users to operate on different components of the computer and operating system.

useradd - Adds users to the system.

userdel command - Deletes users from the system

V

Vertical sync - The number of whole screens per second, the monitor is able to update.

vi - a text editor

Vim - Vi improved. Vim is a clone of vi and works in a similar fashion.

Virtual console - Terminal that uses the same display and input as another console. There are usually 6 virtual consoles available. Users use the ctrl+alt+F key to reach the virtual console.

Virtual desktops - Organize and collect workspaces together

Virtual filesystem - Rather than writing functions for every filesystem Linux supports, functions are written for an interface to all filesystems called the virtual filesystem.

W

Window managers - The GUI shell that gives users access to the move, resize, close, and similar functions.

Workspaces - Provide separate screens in one monitor to do work in. This helps eliminate clutter on the desktop

X

X - The X-Window-System

x86 - CISC processor used in majority of desktop computers.

x86_64 - 64 bit processors used in the majority of modern desktop computers

X Window System - Consists of the X server, the libraries programs use to talk to the X server, rendering functions and network transparency functions for remote access.

x terminal - Terminal that runs on the X-Window-System

xfce - Another desktop environment

Y

Z

zsh - Z shell, an alternative to bash