Web Lingo

As you remember from class, I explained the term "protocol". I mentioned that it was an agreed-upon way of communicating. I started speaking in Spanish and only one person in the class had any idea what I was saying. As you are aware by now, there is a terminology to all things Internet-related. It's important to understand the terminology because we are going to be using these terms again and again throughout the class. This is our kind of "protocol", so that when I am speaking, the things I say are not travelling over your head.

You will responsible for understanding all the following terms. Please have these committed to memory.

Alias
n. Nickname. In DNS, often there will be a few aliases that actually point to the same web host. For example, www.bachboerne.org, ftp.bachboerne.org and mail.bachboerne.org all point to the same IP address.

ARPA (Advanced Research Project Agency)
n. Dept. of Defense agency established in response to Soviets' lead in space race after the Sputnik launch. One of ARPA's legacies is ARPANET, the predecessor to the Internet.

ARPANET
n. Predecessor to the Internet. It included several remote computers which could exchange information over long distances.

Attachment
n. A file that is sent together with an e-mail message. This file can be saved to the user's computer. Some attachments are E-mail worms that can harm a user's computer or other computers on the network.

Authentication
n. The requirement that a client supply a username and password to access a file or other resource on a network, including the Internet. You must be authenticated on the Web 101 website before you can do your homework, for instance.

Binary
n. Data that can contain any of 256 characters in the ASCII "alphabet". Executable programs, images, music and compressed ZIP files are all binary.

Broadband
n. Any Internet service that is faster than a modem or ISDN dial-up connection.

Browser
n. An executable program that is used to display HTML graphically. Netscape, Internet Explorer and Opera are popular examples.

Bug
n. A flaw in a computer program that causes it to operate incorrectly or unexpectedly.

CAT-5 (Category 5)
n. A commonly used type of cabling used for computer networking using Ethernet. CAT-5 cable has eight internal wires, but only four are used for actually transferring data on a 100-Base-T network.

Client
n. (1) A computer that consumes services provided by other computers, (2) an executable program that requests services from other computers. FileZilla is an FTP client, a web browser is an HTTP client, and Outlook Express is an e-mail client.

DNS (Domain Name System)
n. Hierarchical naming system for computers on the Internet. The DNS guarantees the uniqueness of the name of each computer and web page.

Domain
n. A name that has been registered with a domain registrar, to be used to uniquely identify computers on the internet. "Bachboerne.org" is an example of a domain.

Download
v. To transfer a copy of a file from a server computer to a client computer. n. Downloaded information or files.

DSL (Digital Subscriber Line)
n. A service provided by a telephone company which provides high-speed Internet access through existing phone lines.

Ethernet
n. Hardware for transferring information between computers on a network. Ethernet is the most commonly used networking hardware, and it includes "ethernet adapters" in computers, CAT-5 cabling, routers, hubs and switches.

E-mail
n. Messages sent from a "sender" to one or more "recipients" across a network or the Internet. Messages may be sent using SMTP and received using POP3. Web mail is also classified as e-mail. E-mail may have attachments. v. To send an e-mail message.

Executable
n. An executable file is a program or code that runs on a user's computer. Executable files usually have the ability to modify a user's computer system and gather data from the hard drive and local network.

File
n. A file is a unit of data stored on a computer's hard drive. All files have a unique name in the computer's file system. Files may contain text, HTML, data, images, music, or executable programs and scripts.

Firewall
n. A piece of hardware or a software program which prevents or filters incoming Internet requests to a computer or network. ZoneAlarm is a software firewall, the SMC Barricade that I showed in the back room is a hardware firewall.

FTP (File Transfer Protocol)
n. This protocol is a means of transferring files between computers across a network or the Internet. Using FTP, one may download files from or upload files to an FTP server. FileZilla is an FTP client program that can be used for FTP. v. To use an FTP server.

FTP Server
n. (1) A program that runs on a server which permits files to be transferred to and from remote client computers. (2) A computer running FTP server software.

Host
n. Any computer that is connected to the Internet. v. To offer the use of one's computer as a web server to someone else, often for a fee.

HTML (Hypertext Markup Language)
n. HTML is a formatting language used to display text and images in a web browser. Modern HTML may include the ability to host executable content such as Java applets, Flash movies and JavaScript code.

HTTP (Hypertext Transfer Protocol)
n. The protocol for transferring data from a web server to a web browser or other HTTP client. It is the "rude" protocol, with a typical sequence of "connect - request - response - disconnect". Most web pages are delivered using HTTP.

Hub
n. A piece of Ethernet equipment used to connect several local computers.

Hyperlink
n. On a web page, a hyperlink is a place in the browser where you can click to jump to another related page. v. To reference another web page using a hyperlink.

Hypertext
n. A text format that contains hyperlinks and images. Hypertext is usually displayed using HTML, but other formats such as Adobe Acrobat PDF and Rich Text Format can be classified as hypertext as well.

Internet
n. The global network of computers that communicate using the TCP/IP protocol (and other protocols).

IP Address
n. A four-number sequence that uniquely identifies a host on the Internet. The four numbers may each range from 0 to 255. Example: 12.145.12.85 is the IP address for bachboerne.org.

ISP (Internet Service Provider)
n. Anyone that provides access to the Internet, usually for a fee.

Mail Server
n. (1) A software program that can receive and send e-mail messages from remote clients. Typically a mail server includes an SMTP program for sending messages and a POP3 server for users to download their messages. (2) Any computer running a mail server program.

Modem
n. A device used to connected two computers in a network using ordinary phone lines. Many ISPs use modems to provide Internet access to customers for a fee.

Name Server
n. (1) A software program that can resolve a domain name to an IP Address. The BIND program is a common name server program on Unix. (2) A computer running a name server program. In Windows NT, 2000 and XP, you can use the 'nslookup' program on the command line to manually issue a DNS query to a nearby name server.

Network
n. Two or more computers that are connected so they can transfer data. v. To connect computers so they can transfer data.

P2P (Peer-to-peer)
n. A software program that both acts as a server and a client that is used for exchanging files or text. Common P2P programs include Kazaa, AIM, MSN Messenger, Netmeeting, Yahoo Messenger and ICQ.

Packet
n. A small unit of information transferred across a network. A file transfer or web page download may involve several packets.

Patch
n. A fix to an existing computer program, to fix a bug or a security hole. It is recommended that users apply the necessary patches to their software to protect them from known vulnerabilities. v. To apply a patch.

Path
n. A unique location of a file in a hierarchical naming system, such a computer operating system or a web site. On Windows XP, the path to the system files is C:\WINDOWS\SYSTEM32, for instance.

Ping
v. To send a signal to a specific computer (or router) to test whether it is connected to the network or Internet. If the computer is connected, it will respond affirmatively. n. The act of pinging.

POP3 (Post Office Protocol, version 3)
n. This is the protocol by which a client my read and download e-mail messages from a mail server. POP3 requires the client to authenticate using a username and password.

Port
n. When a server receives information from the Internet, it uses the port number to determine which running server software should receive the information. Ports can be numbered from 1 to 64000. Some ports are used for commonly used services. For example, most web servers "listen" to port 80 for web page requests, and FTP servers "listen" to port 21.

Protocol
n. In the broadest sense, a protocol is an agreed-upon way of communicating. TCP/IP is a protocol for sending raw data from one computer to another. Some protocols determine the commands and responses by which a client and server computer communicate. HTTP, SMTP, FTP and POP3 represent this kind of protocol.

Query String
n. This is extra information at the end of the URL that directs the web server script to behave a certain way. It is the text after the question mark (?).

RFC (Request for Comment)
n. These are the technical documents that define the specification by which a networking protocol is implemented. Through the process of iteration, refinement and revision, we have arrived at several protocols through the RFCs. The RFCs have been superceded by the W3C recommendation procedure.

Router
n. A piece of network hardware that is responsible for transferring information between two Internet-connected computers. When you download a web page from a web site, the information will travel through about ten to thirty routers between the client and server computers.

Script
n. A script is a unit of text that contains commands that can be executed by a "script interpreter". Scripts can be considered to be executable. Scripts can be used for either good and evil. Many web pages are scripts that run programs on the web server. Some web pages contain scripts that run in a web browser for appealing effects. Some scripts are worms that are sent via e-mail attachments and may cause destructive consequences if executed on a user's computer. v. To write a script.

Server
n. (1) A piece of software the provides services, data and resources to other computers on a network. (2) A computer that is running a "server operating system" such as Windows 2000 Server or Unix.

Service Pack
n. A patch to an operating system or server program. See Patch.

SMTP (Simple Mail Transfer Protocol)
n. This is the protocol by which a client my send e-mail messages to recipients. SMTP servers send e-mail messages between each other using "message relaying".

Socket
n. A software program that simplifies the process of creating a program that can send and receive information on a specific port on a network. This frees a programmer from needing to implement the low-level details of TCP/IP programming, and concentrate on higher protocols such as HTTP, FTP, etc.

Spam
v. To send unsolicited e-mail messages. n. See UCE

Switch
n. A piece of Ethernet hardware used to distribute network connectivity among several computers. A switch is similar to a hub, except that it redirects traffic to specific computers, whereas a hub broadcasts to multiple computers. v. To change the destination of a TCP/IP packet.

TCP/IP (Transmission Control Protocol/Internet Protocol)
n. This is a protocol by which information is transferred between computers using a "packet-switching" schema. TCP/IP is the predominant method of data transfer on the Internet (although there are others, including UDP and ICMP (ping), not discussed here). TCP/IP guarantees that each packet will reach its destination in the correct sequence.

Telnet
n. A program that is used to remotely control computers over a network. Telnet programs can be used to manually communicate with servers on the Internet. I demonstrated a Telnet program called "PuTTY" in class, and showed how you can send an HTTP request to a web server and manually send an e-mail message by directly communicating with an SMTP server. v. To use a telnet program to access a server.

Text
n. Character data (letters, numbers and symbols) that is more or less legible to human readers. Plain Text, scripts and HTML are examples of text files.

TLD (Top-level domain)
n. The last part of the full domain name is called the top level domain. .com, .net, .org, etc. are top-level domains.

UCE (Unsolicited Commercial Email) aka "Spam"
n. E-mail messages randomly or semi-randomly sent to recipients to advertise goods or services.

Unix
n. A computer operating system that has networking as an integral part of the system. Unix has a hierarchical file naming system, and most modern operating systems (like Windows and Mac OS) use the same type of hierarchical file naming. An open-source version of Unix called Linux is becoming increasingly popular today.

Upload
v. To copy a file from a client computer to a server. File are usually uploaded by FTP, less often by HTTP. n. Uploaded files.

URL (Uniform Resource Locator)
n. The is the unique name for anything that can be found on the Internet. In your web browser, when you mouse over a hyperlink, you can often see the URL of the hyperlink in the status bar at the bottom of the window. The Address Bar of your browser contains the URL of the web page you are currently viewing.

Virus
n. A virus is a small piece of executable code that is embedded in an executable program and requires the execution of that program to replicate. Some malicious viruses can be very destructive to computers or entire networks.

W3C (World Wide Web Consortium)
n. This is a collaboration of academic and industry Internet experts that defines the standards used for Internet protocols. When a standard is accepted, it receives a "W3C recommendation", which is the approval needed to gain acceptance among web professionals.

Web Mail
n. Web mail is the use of a web site to send and receive e-mail via a web page rather than the more conventional SMTP and POP3. The advantage of web mail is that all the SMTP and POP3 client setup is done at the web site instead of the user's e-mail client program. The disadvantage is that there are usually severe restrictions on how much e-mail a user can "keep".

Web Page
n. A file located on a web server that can be accessed from a web browser by its URL. Some web pages are "static" HTML - meaning that the content must be manually edited. Other web pages are executable web server scripts that generate and transfer HTML depending on various parameters, search criteria, etc.

Web Server
n. (1) A software program that is responsible for delivering web pages to clients via HTTP. Many web server programs have scripting capabilities to provide interactive content. (2) A computer that runs an HTTP server.

Web site
n. A collection of mutually-linked web pages on a web server, usually under a single domain or path.

World Wide Web
n. A broad generic term for the expanse of web sites located across the Internet.