Specifies a collection of the name/value pairs that make up the HTTP headers.
Assembly: System (in System.dll)
The collection contains the protocol headers associated with the request. The following table lists the HTTP headers that are not stored in the collection but are either set by the system or set by properties or methods.
Set by the Accept property.
Set by the ContentLength property.
Set by the ContentType property.
Set by the Expect property.
Set by the Date property.
Set by the Host property.
Set by the IfModifiedSince property.
Set by the AddRange method.
Set by the Referer property.
Set by the UserAgent property.
You should not assume that the header values will remain unchanged, because Web servers and caches may change or add headers to a Web request.