HTTP1.1
HTTP/1.1, an upgrade from the original [[HTTP1.0|HTTP/1.0]], has been the standard web protocol for many years. It introduced several enhancements like persistent connections, chunked transfers, and additional cache control mechanisms.
However, it processes requests sequentially on each [[Transmission Control Protocol|TCP]] connection, which can lead to inefficiencies and slower performance (a problem known as "[[Head-of-Line Blocking]]").
In terms of security, HTTP/1.1 itself is not inherently insecure, but it lacks encryption. When used over [[TLS]] ([[HTTPS Protocol|HTTP]]), it's secure against eavesdropping and tampering.
Comparatively, [[HTTP2|HTTP/2]] offers significant improvements:
HTTP/2's multiplexing allows multiple requests and responses simultaneously over a single connection, reducing latency. HTTP/2 can send resources proactively, not just in response to requests. This makes HTTP/2 more efficient in parsing and reduces errors compared to HTTP/1.1's text-based approach. It reduces overhead, especially in scenarios with many small requests.