As a reminder, the HTTP protocol (Hyper Text Transfer Protocol), is a mechanism used by Internet browsers to request information from the web server and display pages on the screen of the device being used.
The HTTP/2 protocol is the most modern and powerful version of this protocol.
It is important to use the HTTP/2 protocol rather than the old one because it is more powerful and allows users to enjoy a better browsing experience. This is possible because the HTTP/2 protocol reduces the weight of requests by compressing headers and also connections, called request multiplexing (sending multiple requests on the same connection).
The protocol has to be set up on the web server of the site.