q).what is http?
*. HTTP = a protocol used to transfer information over the world
   wide web.
*.It is the foundation of data communication on the Internet.

q).will http use UDP?
*.No, HTTP protocol that is typically run on top of the TCP or sometimes on top of a secure SSL/TLS connection. It is not designed to use the UDP as a transport protocol.

q).How http works?
*.when you access a website, your browser sends a request to the
  relative web server and it responds with a http status code.
*.If the URL is valid and connection is proper. web server sends
  a standard html format and other related files.

q).What are all request Methods?
*.To make a request, Client will use existing HTTP METHODS.
*.eg: GET,PUT,POST,DELETE.

q).examples of status code?
*.After the request received form the client. the webserver will
  response to the client with a return code.
*.200 - OK
  404 - not found
  301 - moved
  401 - unauthorized request
  403 - forbidden 

q).What about HTTPs? 
*. HTTPs = encrypted HTTP connection.
*. They made with available SSL/TLS nowadays.  

Http Key components

Client:
*.The initiator. the home web browser. you are the client that
  something trying to search in web browser.
*.In the backend of the system. your browser make a request to 
  server of the website in the URL, in order to get specific
  information which we specified,
Server:
*.Server or Web Server.
*.Which responds for all Http requests with return codes and
  followed with data.
Proxy:
*.It can be computer/router/server. It can either alter the
  response that is getting sent or leave as it is.

Http Sessions and Cookies:

Sessions work with the use of cookies and cryptographic techniques to maintain a state without storing as much data on the server.
q). What is Cookie?
*. Cookie is a state data of a dynamic web page at a given point
   of time.
q). why we introduced cookies?

q). Cookies. is it necessary?

q). Is it Session must to use Cookie?

q). How Cookie contribute in terms of http?

q). fun fact on Cookie?
q).Cookie. data stored on client. -- is it Vulnerable?
*.Data integrity: no third party allow to handle client data at
  any cost even in accidentally/maliciously other than a server.
*.authenticity confidentiality: Sessions must be able to initiate
  by the server only. not by any other. 
q).holding cookie on client side makes disk space right?
*.the server might compress the data before it sending to a
  client. and server can decrypt it once returns from client.
*.compressing a data in a cookie is a good technique, to keep 
  occupies less disk space in client side.
q).Is cookie relevant to client or server?
*.cookies are relevant to both the client and the server.