HTTP request: Every HTTP message sent from a web browser to a web server is classified as an HTTP request.
HTTP response: Every message sent from a web server to a web browser is classified as an HTTP response.
Request methods:
GET: A GET request is basically a request to receive the content located at a specific URL.
PST: It is commonly supported by browsers as a method of submitting form data, the browser will send the data from the form fields in a POST request.
PUT: It allows the web client to send content that will be stored on the web server. It behaviors like an update action on web server.
DELETE: It will specify the content on the web server to be deleted as the resource in the request line.
HEAD: The HEAD method is supposed to behave exactly like GET, except that the content is not present.
TRACE: TRACE is another diagnostic request method; this method allows the client to gain more perspective into any intermediary proxies that lie between the client and the server.
OPTION: It is used to identify the capabilities of the web server you want to interact with prior to actually making a request. List all the methods supported by web server.
CONNECT: The connect method is reserved explicitly for use by intermediary servers to create a tunnel to the destination server. The intermediary, not the http client issues the connect request to the destination server.
An HTTP response is broken into the following three logical pieces:
1. status line 2. http headers 3. Content
There are three types of http headers in a response:
1. General headers. 2. Response headers 3. Entity headers