HTTP protocol: HTML only?

My informatics teacher explained that HTTP can really be used exclusively开发者_Go百科 to transfer unencoded ASCII, and as soon as an image or the like have to be downloaded from the server, FTP is used instead.

Is this true?

No, it isn't. HTTP contains a header and data part, the latter gets interpreted by the receipent according to the CONTENT-TYPE header. HTTP can transfer arbitrary data.

If you want any more specific information about the HTTP protocol, the full RFC (request for comments) document is available here: http://www.w3.org/Protocols/rfc2616/rfc2616.html

An RFC is where the various different parties who have a stake in these protocols are presented the current version and invited to give their opinion. It's the method by which most of the internet has been built :)