HTTP/2 is the second major version of the Hypertext Transfer Protocol (HTTP), which is the protocol used for transferring data over the web. HTTP/2 was introduced to address some of the limitations of HTTP/1.1, particularly in terms of performance and efficiency. It was designed to improve page load times and overall web performance by reducing latency, minimizing bandwidth usage, and allowing for more efficient data transmission between web servers and clients (browsers).

Some of the key features of HTTP/2 include:

Multiplexing: One of the most important features of HTTP/2 is its ability to multiplex multiple requests and responses over a single TCP connection. This eliminates the need to open multiple connections for fetching different elements of a webpage, as was common in HTTP/1.1, where each request had to wait for the previous one to finish (head-of-line blocking). Multiplexing allows for more efficient use of network resources and faster page load times.

Header Compression: HTTP/2 uses a technique called HPACK to compress HTTP headers, which reduces the amount of data that needs to be transmitted. In HTTP/1.1, headers were often sent repeatedly with each request, leading to redundant data transfer. HTTP/2 solves this by compressing and encoding headers, further improving performance.

Server Push: Another significant feature is server push, which allows the server to send resources to the client before they are explicitly requested. For example, if a client requests an HTML file, the server can "push" additional assets like CSS or JavaScript files that it knows will be needed. This reduces the number of round trips between the client and server and speeds up the rendering of webpages.

Binary Protocol: Unlike HTTP/1.1, which used a text-based protocol, HTTP/2 uses a binary format. This makes it more efficient for parsing and allows for more robust communication between clients and servers.

In conclusion, HTTP/2 brings significant improvements over HTTP/1.1, focusing on speed, efficiency, and reduced latency. It has become the standard for modern web communication, helping websites load faster and improving the overall user experience.