Many web developers using HTTP don't think about the protocol itself. This site should provide a basic understanding of HTTP 1.1 and ease the development of web applications that use HTTP.
GET request you can
retrieve the content of a resource.
PUT request you can
create a new resource or
replace the content of a resource.
POST request you can
send data to be processed
by the given resource.
DELETE request you can
remove a resource.
HEAD request you can
check the condition of a resource. This
request is identical to the
GET request, but
it does not return any content.
OPTIONS request you can
retrieve the capabilities of a resource.
The responses 200 to 299 indicate, that the request was successful.
The responses 300 to 399 indicate, that the request should be send to another resource.
The responses 400 to 499 indicate, that the request was malformed.
The responses 500 to 599 indicate, that the request couldn't be answered because of a server error.
Now that you know the more or less important glimpses about HTTP 1.1 you could dig a bit further.