Web and HTTP
A web page consists of objects defined by HTML. Eachobject is accessible via a URL. The application protocol for the web is HTTP, which is based on a client / server system. HTTP uses TCP port 80 for the transfer.
The client opens connection with a servant, whose task isto accept it. Messages are exchanged between browser and web-server. HTTP does not remember previous requests(is stateless).
In the version we ship only item on the HTTP1.0connection (not persistent), with HTTP1.1 is not possible to send multiple objects.
The response time of HTTP is equal to two times the Round Trip Time (RTT) added to the time of transmission.
In HTTP1.0 each object has to "waste" a time of 2 RTTconnection, as the persistent connection is not closed andso the time is "only" 1 RTT in HTTP1.1 you may have and we waste a pipeline RTT only for all objects.
GET produces the transfer of the response specified in the URL field. If the request is an object to be processed and the result is sent. It has several variants.
POST sends the data to the resource pointed to by URL. Used to annotate a resource, send parameters, send messages.
HEAD: how to get but the response headers only and is not affected.
PUT: request made by the entity creating content URL is not sent. If a match overrides it.
DELETE: requires the delection of URL and its contents.
OPTIONS: for different other kind of service
TRACE: invoke a loop-back. No entities and serves as verification.
CONNECT: for the proxy