Something that is more and more neglected these days. With the introduction of the
WWW this
protocol definition has been omitted due to
marketability. It simply doesn't look good enough with this
mumbo-jumbo in
ads for
major companies's
homepage addresses.
HTTP is short for HyperText Transfer Protocol and is used to tell the user agent which protocol should be used when decoding the data received from the request given.
Back in the day there used to be more protocol definitions as well. Like for example "ftp://", "gopher://", "wais://" and others. Although nearly extinct they still lurk out there. The only one that gets fair usage, apart from the very common http:// is the ftp://-definition.
Ignorant users don't believe it is necessary to apply this prefix to an address, but believe me, it is. I usually do it just to be sure I get the right page. Your user agent does that automatically, look up at the location bar at the top of your browser right now, does it say "www.everything2.com" or "http://www.everything2.com". I'd bet it's the latter, am I right?
See? The browser inserted this although you typed in the address without it.
Yes, there is also news:. Actually, the correct format is in the form of the news-example. All you with some experience from web design know of the dreaded mailto: saying. This is also a protocol-definition. But it is not actually a protocol but instead an instruction to the browser on what to do with the link, i.e. start the mail composer.