Q:

What is the form collection in asp.net/html?

Simple question but one i need to clarify for myself. In terms of collections that can be accessed in the request object there is:
Cookies:    (whats in  a text file in the browser)
Querystring:   (whats passed in the url like [key=value&key=value etc])
Server Variables:  ?
Form Variables:    ?

The ones with the ? next to are the ones that I dont really understand where in the http packet/html they are placed. I did a capture using wireshark:
POST /Security/HelixSessionAuth.aspx HTTP/1.0
Content-Type: application/x-www-form-urlencoded
Content-Length: 391

ClientIP=192.168.20.31
Url=%2Fflash%2F56553550%5Fhi%2Emp4
Log=SESSIONSTART%20%5B13%2FDec%2F2010%3A16%3A31%3A23%20%2B0000%5D%20%20flash%2F56553550%5Fhi%2Emp4%200%20192%2E168%2E20%2E31%203%20%5B13%2FDec%2F2010%3A16%3A31%3A23%20%2B0000%5D%200%200%200%20%5B0%20No%20Error%5D%20%5B0%20No%20Error%5D%20%5Brtmp%3A%2F%2Fhelix%2Epete%2Evideolibraryserver%2Ecom%2Fflash%2F56553550%5Fhi%2Emp4%5D%0A
HTTP/1.1 404 Not Found
Content-Type: text/html; charset=us-ascii
Server: Microsoft-HTTPAPI/2.0
Date: Mon, 13 Dec 2010 16:31:23 GMT
Connection: close
Content-Length: 315

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN""http://www.w3.org/TR/html4/strict.dtd">
<HTML><HEAD><TITLE>Not Found</TITLE>
<META HTTP-EQUIV="Content-Type" Content="text/html; charset=us-ascii"></HEAD>
<BODY><h2>Not Found</h2>
<hr><p>HTTP Error 404. The requested resource is not found.</p>
</BODY></HTML>

Where abouts would they be in the above feed?

A:

The Form collection is the list of controls in the page that are passed to the action page via the POST method. Querystring is a GET, POST adds items to the Form collection. If you know the name of the control in the POST, you can access its value in the action page using:
Request.Form("myControl")

In .Net web forms, this is a little more complicated because .Net injects a specialized ClientID to preserve the ID of the actual control in the code behind.
The server collection is a collection of common server variables identifying information about the client, server, connection, browser, etc. A full list can be found here:
https://msdn.microsoft.com/en-us/library/ms524602(v=vs.90).aspx

