Jargon Website Development

AJAX	Asynchronous JavaScript and XML. A framework that enables web pages to exchange data with a web server without reloading the entire page, thereby creating a more seamless experience for a visitor.
Apache	Apache Software Foundation, a non-profit corporation that oversees several important software projects, one of which is the Apache HTTP Server, the world’s most popular web server.
ASP	Active Server Pages. Microsoft’s server-side scripting technology for dynamically generated web pages. An add-on to IIS.
attribute	An optional modifier of an HTML or XHTML element. Each attribute necessitates a value, and an element may have zero or more attributes.
C++	A programming language developed in the 1980s by Bjarne Stroustrup of Bell Labs. It originates from two older programming languages, C and Smalltalk, combining the computing power and low-level functions of the former with the object-oriented model of the latter. C++ used to be the most popular programming language for about a decade, losing some of its advocates to Java and C#.
CGI	Common Gateway Interface. A standard for passing data between a client and a webserver. Allows a client’s web browser to use data from a program executed on the web server.
CSS	Cascading Style Sheets. A language used to describe the presentation of a document written in a markup language. Commonly used to style webpages written in HTML or XHTML.
DHTML	Dynamic HTML. Denotes a collection of technologies collectively used to create dynamic web pages. These technologies include a static markup language (HTML or XHTML), a stylesheet language (CSS), and a client-side scripting language (JavaScript).
doctype	Document Type Declaration. A declaration that associates a markup document with its type definition. A doctype declaration has to present in all XHTML documents for them to be valid.
element	A lexical unit of an HTML or XHTML document demarcating its content. Elements generally consist of three parts: a start tag marking the beginning of an element, some amount of content, and an end tag.
hexadecimal	Of or relating to the base-16 numeric system. Uses the digits 0 – 9 and the letters a – f (to represent the values 10 – 15). For example, the hexadecimal number 3f is 63 in decimal (3x16 + 15) and 00111111 in binary.
HTML	HyperText Markup Language. A markup language used to create webpages viewable in a browser. Structures information with tags, denoting parts of text as headings, paragraphs, hyperlinks, etc.
httpd	Apache’s HTTP server.
IIS	Internet Information Services. A set of Internet-based services for Microsoft Windows-based servers, and the second most popular webserver after Apache.
Java	A programming language developed by James Gosling and his team at Sun Microsystems. Its stricter object model, easier syntax, and powerful networking features made the language a strong competitor to C++. Java is, arguably, the most popular computer language today.
JavaScript	An object-oriented programming language mostly used to create dynamic content in web pages. It has C-like syntax and is similar to other scripting languages, having little to do with Java, despite its name.
JSP	JavaServer Pages. A Java-based technology that allows for dynamic generation of HTML and XHTML.
octal	Of or relating to the base-8 numeric system. Uses the digits 0 – 7. For example, the octal number 125 is 85 in decimal (1 82 + 2 81 + 5 80) and 55 in hexadecimal.
parse	To analyze a stream of input (such as a computer program) to determine its grammatical structure and break it down into individual tokens.
Perl	Procedural programming language created by Larry Wall. Its compact syntax and large collection of text-processing functions make it the language of choice for quick information-processing scripts, but it may not be feasible to creating largescale applications. It has been “backronymed” as Practical Extraction and Report Language.
PHP	“PHP: Hypertext Processor” (a recursive acronym) or “Pretty Hypertext Processor”. A programming language used to create server-side applications and dynamic web content. A popular alternative to Microsoft’s ASP technology.
pretty-print	To present an object (such as a webpage, or part thereof) in such a manner as to make its structure easier to perceive (e.g., nicely indented with frequent line breaks).
property	A feature of an HTML or XHTML element that can be controlled by CSS; a property has a value associated with it, usually written as property: value.
script	A program written in a scripting programming language.
SSI	Server Side Includes. A server-side scripting language primarily used to include contents of a file.
stylesheet	A language used to describe the style of elements in a document marked up using a markup language. CSS is the widely used stylesheet language for HTML and XHTML today.
tag	A label used to include metadata to the contents of a document. In HTML and XHTML, tags are used to demarcate the beginning and end of a certain representation of information. For example all text between the <b> and </b> tags will be bold, and everything between the <p> and </p> tags will be considered a paragraph. Many tags also have a set of optional attribute="value" pairs.
valid	An XHMTL document is said to be “valid” if it conforms to a doctype (i.e., contains no errors).
web-safe colors	Any of the 216 colors originally used in webpages.
webserver	A computer that receives HTTP requests from clients’ web browsers, and in return serves them webpages, which are usually HTML or XHTML documents. Also, a computer program that provides the functionality just described.
well-formed	An XHTML document is said to be “well-formed” if, among other things, all elements’ and attributes’ names are in lowercase, all attributes’ values are flanked by single or double quotes, and all tags are balanced.
XHTML	eXtensible HyperText Markup Language. Has the same expressive capabilities as HTML, but a stricter syntax, which allows for better automation of data processing. Specifically, XHTML requires that all webpages written in it be well-formed.

Jargon

The Internet

blind carbon copy BCC. Used for sending messages to recipients such that the targeted recipients

(TO and CC) are unaware of the BCC’d party’s receipt of the email.

blog Short for “web log,” blogs are generally thought of as frequently updated online

journals.

carbon copy CC. A method of copying email messages to a third party.

CC See carbon copy.

chat Real-time-communication system for users on networked computers.

client A host or software running on a host that uses a remote service on another

computer (a “server”).

ccTLD Country Code TLD. Two-character abbreviation for countries’ names used as

TLDs.

domain A group of related computers that share some logical connection. Also the name

of such a group (e.g., harvard.edu).

email Electronic mail.

email address An address (often of the form username@domain.tld or

username@subdomain.domain.tld) that identifies a user’s email inbox on the

Internet.

emoticon Short for “emotion icon” (aka a smiley :-).

GET HTTP command to retrieve webpages

HTTP Hyper Text Transfer Protocol. The language webservers and web browsers use to

communicate.

IM Instant Messaging. A means by which to conduct a real-time, text-based

conversation.

IMAP Internet Message Access Protocol. A language clients and servers use to exchange

email from the latter to the former that allows subsequent changes on the client to

be mirrored on the server.

instant message See IM.

internet A large network made up of a number of smaller networks.

Internet The global network of networks.

intranet A (typically private) network meant for use within a specific organization or group.

LAN Local Area Network. A relatively small network usually comprising geographically

proximal computers.

listserv A type of mailing list program that allows users to self subscribe to communities of

interest.

netiquette Internet etiquette.

network An interconnected system of computers.

P2P See peer-to-peer.

peer-to-peer A means of sharing and delivering files among hosts on a network

POP Post Office Protocol. A language clients and servers use to exchange email from

the latter to the former that does not allow subsequent changes on the client to be

mirrored on the server.

server A host that runs a service, such as email.

SFTP Secure File Transfer Protocol. A language used by clients and servers to exchange

files via encryption.

SMTP Simple Mail Transfer Protocol. A language used by clients in servers to deliver

email from the former to the latter.

snail mail Regular mail delivered by the United States Postal Service.

spam Unsolicited junk email.

Computer Science E-1: Understanding Computers and the Internet

Harvard Extension School

Fall 2006

– 3 of 3 –

SSH Secure Shell. A language used by clients and servers to allow a user on the former

to access and control an account on the latter.

subdomain A domain-within-a-domain typically representing some logical subdivision of a

larger entity. For example, fas.harvard.edu is a subdomain of harvard.edu.

surf A term used synonymously with “browse” to indicate a casual perusal of content

on the Internet.

TLD Top-Level Domain. The “top” of the domain structure, hierarchically speaking.

Semantically, the last portion of a domain name (e.g. .edu, .com, .net, .org, .uk).

URL Uniform Resource Locator. A unique address for electronic resources (e.g.,

webpages) available on the Internet, typically of the form

protocol://host.domain.tld/path.

Usenet A collection of newsgroups (i.e., bulletin boards or message boards).

WAN Wide Area Network. A relatively large network usually comprising multiple LANs.

weblog See blog.

WLAN Wireless Local Area Network. A relatively small network usually comprising

geographically proximal computers connected wirelessly.

World Wide Web A network of hosts on the Internet that serve content via the HTTP protocol.

The Internet, Continued

1000Base-T An Ethernet system that supports a data transfer rate of 1000 Mbps (i.e., 1 Gbps)

over a twisted-pair cable.

100Base-T An Ethernet system that supports a data transfer rate of 100 Mbps over a

twisted-pair cable.

10Base-T An Ethernet system that supports a data transfer rate of 10 Mbps over a twistedpair

cable.

802.11b A WLAN specification that supports a maximum data transfer rate of 11 Mbps.

802.11g A WLAN specification that supports a maximum data transfer rate of 54 Mbps

and is backwards-compatible with 802.11b.

ACK “Acknowledge”, a type of packet sent in response to data traffic.

backbone A conduit for traffic between networks that typically operates at a very high

speed and capacity.

bandwidth A measure of data transmission often used to describe the maximum amount of

information that can be sent over a particular medium (such as a cable modem

connection) in a particular amount of time (e.g., megabits per second).

beaming A method of wireless transmission (e.g., IR).

Bluetooth A wireless technology typically used in Personal Area Networks (i.e., cell phones,

PDAs, headphones, etc.).

broadband Network connection accommodating multiple data streams (implies a highbandwidth

capacity).

bus network A network in which all of the nodes are connected to the same cable.

cable A physical medium (copper or optical) for transmission.

cable modem A device for use with cable TV service that allows for simultaneous data

networking.

crossover cable Type of twisted-pair cable with the send and receive wires crossed.

datagram A unit of transmission in a TCP network.

DHCP Dynamic Host Configuration Protocol. The “language” spoken by DHCP

servers with computers on a network in order to provide the latter IP addresses

and other settings.

dialup modem A networking device used to connect a host to a network over phone lines.

DNS Domain Name System. The service that translates names to IP addresses

(e.g., www.fas.harvard.edu to 140.247.34.66).

DSL Digital subscriber line. A means of transmitting network traffic over copper

phone lines.

Ethernet The most commonly used LAN technology, originally developed by Xerox,

Ethernet is used for sending data over coaxial or twisted-pair lines. Data is sent

to MAC addresses.

Ethernet

address

See MAC address

fiber-optic

cable

A thin, flexible cable with an essentially glass core surrounded by a protective

coating, fiber-optic cable transmits data using light rather than electricity.

fragment A piece of data. In networking (such as TCP/IP), large chunks of data are often

fragmented, transmitted, and reassembled at the receiver’s end.

frequency The number of occurrences in a given time period, often expressed in cycles such

as Hertz (Hz) or Megahertz (MHz).

header Block of information at the beginning of transmitted information containing

information such as the originator and recipient.

hexadecimal A numbering system based on 16 digits. The first ten digits are represented by 0

through 9, and the next six are represented by A through F.

hub A device that serves as a junction for nodes on a network. It takes an incoming

signal from one port and broadcasts it back on all other ports.

ISP Internet Service Provider. A company that provides users with connections to

the Internet.

MAC address Media Access Control address. Unique address of a physical device on a network

such as a NIC in a PC.

NAT Network Address Translation. A technology that allows multiple computers to

share one IP address.

NIC Network Interface Card. An expansion card that provides a computer with

physical means of being connected to a network.

packet Fundamental unit of information transmitted on a network.

patch cable Also called a straight-through cable, a type of cable used to interconnect

networking devices or other cable.

peering point Points of traffic exchange between ISPs.

port An interface through which data is sent and/or received. Often used to describe

a datajack on a networking device.

ring network A type of network configuration (topology) in which nodes are connected to

each other in a closed loop.

root server A name server (DNS server) that directs requests to TLD name servers.

router A device that routes data from one network to another based on the data’s

source and/or destination address.

Rx Shorthand for “receive.”

sequence

number

An identifier for packets to assist in their verification and reassembly on the

receiving end.

star network Network topology in which all nodes are connected through a central point.

straightthrough

cable

See patch cable.

switch Hub-like device. It is “smarter” than a hub as it does not rebroadcast signals to

all ports, but rather directs signals to a specific node.

TCP/IP Transmission Control Protocol/Internet Protocol. The “language” that

computers on the Internet speak in order to route data among computers.

topology Physical layout of a network.

TTL Time To Live. A sort of half-life measure for packets in a network. Once the

TTL has been exceeded, the packet will no longer be transmitted.

Tx Shorthand for “transmit.”

UTP Unshielded Twisted Pair. Describes a type of cable often used to connect

computers via Ethernet.

warchalking The practice of marking areas with accessible wireless networks.

wardriving The practice of looking (by car) for accessible wireless networks.

WEP Wired Equivalent Privacy. A (somewhat easily broken) form of encryption that

can be used by computers to encrypt data between them and a wireless access

point or router.

WiFi Synonym for wireless 802.11 networks.

WiMAX A wireless technology of increasing popularity, capable of greater distances than

802.11 networks.

WPA WiFi Protected Access. A form of encryption (superior to WEP) that can be

used by computers to encrypt data between them and a wireless access point or

router.

Multimedia

AVI Audio Video Interleaved. A video file format for PCs.

bitmapped

graphic

An image defined with a grid of pixels (instead of with a set of mathematical

formulae).

BMP An uncompressed, bitmapped file format commonly used as wallpapers on PCs

running Windows.

CD-DA Compact Disc-Digital Audio. The audio file format for music CDs.

DivX A video file format based on MPEG-4 that compresses file information.

EPS Encapsulated PostScript. A vector-based image file format commonly used for

high-resolution, scalable graphics.

file sharing Allows access to data on a computer over a network.

Flash A vector-based format for animations that also supports audio and video.

GIF Graphical Interchange Format. A lossless image file format originally developed

by CompuServe. Supports 8-bit color, animation, and transparent backgrounds.

Gnutella

network

A peer-to-peer file sharing system.

graphic An image (as opposed to text).

image A visual representation or likeness (as a photo).