Irene Koutsou

I work from a captured exchange, because most disagreement in this area is between a specification and a deployed system. The method says what should happen and the target says to what. Both are selected by the client and neither is a hint, so a request sent with a method the resource does not support is answered rather than interpreted. Redirects are a method change, which is the part people miss. The two that preserve the method are the ones intended for this, and the one that does not will turn a submitted form into a request the server can reject. Choosing by familiarity rather than by semantics is how a login flow breaks on a move. Proxies sit between and each has its own rules. A forward proxy decides what may be reached and may rewrite the target. A reverse proxy decides what may be exposed and terminates the connection to the origin. Headers added by one of them reach the origin and sometimes the client, and the hop count header is what lets the two sides be distinguished. The connection itself matters for behaviour. Persistent connections avoid a handshake per request, and a server with a limit will refuse rather than queue. Protocol versions after the first solve the head-of-line problem that made multiplexing worth the upgrade. Every example includes the exchange as sent and as received, because the header that answers the question is usually on the other side of the connection from the one being examined.