Burp's most amazing feature is the fact that it doesn't hide away the raw HTTP packets behind the pretty GUI. The Message Analysis tab gives you multiple ways to look at and deal with the intercepted requests. The default view is Raw. Have a look at the following screenshot:
The subtabs that can be present include XML, AMF, and View State; these are only available when the request and response are of that type. Have a look at the following subtabs:
Raw: This subtab is a text editor; requests can be changed from here.
Params: This subtab is useful for easy viewing of parameters for HTTP requests. We can edit it by double-clicking on the column.
Headers: Just like Params, name-value pairs are shown in a tabular form. This can be edited by double-clicking on the name-value pairs.
Hex: This gives data in hex format with a hex editor built-in. Individual bytes can be edited by providing hex values.
HTML: If the HTTP response contains HTML in the message body, the HTML...