There are multiple version of HTTP so far! http/1.0, http/1.1, http/2, http/3
Every versions of http has their own advantages and disadvantages of using same connection, TCP etc
This is the first HTTP protocol developed
Each connection uses separate TCP connection, means for eg: if we have a index.js,index.html,index.css when accessing a webpage, for each file there will be every new connection, first index.html will be downloaded using a connection and this will be closed, again a new connection will be established and downloads index.js ... and so on
one can argue, what is wrong with using 3 connections for 3 different files, how does this impact? all these http connections are connected TCP(OSI layer 4). To successfully establish a single TCP connection, one need 3round trip. ok now what does even mean round trip?
TCP is a stateful connection => means to send/receive data the connection pipeline needs to stay active. but the problem with TCP is to establish a single connection we need to perform 3 request(2client and 1server(round trip)).
the client first sends a SYN request to server the server receives and sends a SYN/ACK request to client the client receives and sends the final ACK to server once all the above steps are done, the server and client have now been connected
Now imagine doing all these for every connections, this is what http/1.0 does