http header protocols by nginx.txt

general purpose 2 types while proxying:
1)End to end headers
2)Hop-by-Hop headers(generally not default goes as proxying server is unable to get it by default)
   -apache and nginx alos differ in their own behaviours as apache uses n queen base proxy clusters and nginx we will see below:
   -following are some headers http 1.1 (Important for web socket specially )update and upgrade:
     1.Connection
     2.keep-alive
     3.public
     4.proxy auth
     5.Transfer encoding
     6.upgrade
   -nginx cant default transfers these headers

-other remaining headers are end to end headers above mentioned come under hop-by-hop category