What is a header? Especially, what are POST@GET headers?  
I've been trying to find a Python code that would log in to my Yahoo account from "Google App Engine". One supporter on "StackOverflow" gave me this three-step plan:

   1. Simulate normal login and save login page that you get;
   2. Save POST&GET headers with "Wireshark";
   3. Compare login page with those headers and see what fields you need to include with your request;

The problem here is that I have never used "Wireshark" before. Plus, I don't know what the POST&GET headers are. Can You, please, explain it to me (preferably with some example). Thank You. 
What is a header? Especially, what are POST@GET headers?  
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I've been trying to find a Python code that would log in to my Yahoo account from "Google App Engine". One supporter on "StackOverflow" gave me this three-step plan:

   1. Simulate normal login and save login page that you get;
   2. Save POST&GET headers with "Wireshark";
   3. Compare login page with those headers and see what fields you need to include with your request;

The problem here is that I have never used "Wireshark" before. Plus, I don't know what the POST&GET headers are. Can You, please, explain it to me (preferably with some example). Thank You. 