HTML: HyperText Markup Language. A textual format that marks up text using tags surrounded by less-than and greater-than characters. Example HTML looks like: <p> This is <strong>nice</strong></p>
HTTP: HyperText Transport Protocol. An Application layer protocol that allows web browsers to retrieve web documents from web servers.
IMAP: Internet Message Access Protocol. A protocol that allows mail clients to log into and retrieve mail from IMAP-enabled mail servers.
flow control: When a sending computer slows down to make sure that it does not overwhelm either the network or the destination computer. Flow control also causes the sending computer to increase the speed at which data is sent when it is sure that the network and destination computer can handle the faster data rates.
socket: A software library available in many programming languages that makes creating a network connection and exchanging data nearly as easy as opening and reading a file on your computer.
status code: One aspect of the HTTP protocol that indicates the overall success or failure of a request for a document. The most well-known HTTP status code is “404”, which is how an HTTP server tells an HTTP client (i.e., a browser) that it the requested document could not be found.
telnet: A simple client application that makes TCP connections to various address/port combinations and allows typed data to be sent across the connection. In the early days of the Internet, telnet was used to remotely log in to a computer across the network.
web browser: A client application that you run on your computer to retrieve and display web pages.
web server: An application that deliver (serves up) Web pages