A web browser is a classic example of an HTTP client.
Communication in HTTP centers around a concept
called the request/response cycle, in which the client
sends the server a request to do something. The server,
in turn, sends the client a response saying whether or not
the server can do what the client asked. Figure 7-5
provides a very simple illustration of how a client
requests data from a server and how the server responds
to the client.
Figure 7-5 Simple HTTP Request/Response Cycle
Now let’s look at a request from the HTTP point of view,
where the client (web browser) makes a request (GET
/index.hml) to the server (developer.cisco.com). The
server eventually responds to the client with the actual
HTML page, which then gets rendered by the browser.
Figure 7-6 provides a very simple representation of how
a client sends a GET request requesting the page from
the server and how the server responds with the HTML
page to the client.
Figure 7-6 Simple HTTP GET Request with 200 OK
Response