HTTP Request Methods
HTTP defines methods to indicate the action to be performed on the specified resource. The resource corresponds to a file or the output of an executable residing on the web server. The HTTP/1.0 specification defined the
HEAD methods and the HTTP/1.1 specification added 5 new methods:
CONNECT. By being specified in these documents, their semantics are well supported. Any client can use any method and the web server can be configured to support any combination of methods. If a method is unknown to an intermediate server it will be treated as an unsafe. There is no limit to the number of methods that can be defined and this allows for future methods to be specified without breaking existing infrastructure. For example, WebDAV defined 7 new methods and RFC 5789 specified the PATCH method.