Explain the main principles of the HTTP/2 protocol and how it differs from HTTP/1.1

HTTP/2 is a modern data transfer protocol on the internet that improves performance compared to HTTP/1.1. The main principles of HTTP/2 operation:

• Multiplexing: multiple requests and responses can be transmitted simultaneously over a single TCP connection, eliminating head-of-line blocking in HTTP/1.1.
• Binary protocol: data is transmitted in binary format rather than text, simplifying parsing and increasing efficiency.
• Header compression: uses the HPACK mechanism to compress HTTP headers, reducing the amount of data transmitted.
• Priorities and flow control: the client can set priorities for requests, and the server can manage the data flow to optimize loading.

Differences from HTTP/1.1:

• HTTP/1.1 uses a text-based protocol and opens a separate TCP connection for each request or uses a limited number of parallel connections.
• HTTP/2 operates over a single connection with multiplexing.
• HTTP/2 supports header compression and priorities, which are not available in HTTP/1.1.

Example: in HTTP/1.1, to load multiple resources, the browser opens multiple connections, whereas in HTTP/2, all resources are transmitted in parallel over a single connection, speeding up page loading.