In http transaction for request and response which scenario is occurred ?
- client (web browser) open connection and send it’s request and connection open (keep alive) until server accept and answer then close connection ?
- client (web browser) open connection and send it’s request then connection is closed and server accept and answer and reconnect and send response ?
in http1.0 and http1.1 this scenario is different ?
A server can’t directly reconnect to a client. Hence, your scenario #2 is unlikely.
In other words, in the WEB world, “transactions” between a Client Browser and a WEB Server is always “Client Browser Initiated”.
Of course, if we are talking about server-to-server communication over HTTP, it is a different story: you can make up your own rules here, provided you control at least one server 😉
As for the difference between HTTP 1.0 and HTTTP 1.1, I don’t know enough.