HTTP Caching
Correct caching is the difference between a fast app and an expensive, slow one. Mis-configured cache headers cause stale data bugs and unnecessary origin load.
What It Defines
Defines HTTP caching semantics: Cache-Control directives, cache freshness, validation (ETag, Last-Modified), conditional requests (If-None-Match, If-Modified-Since), Vary, and cache invalidation.
Canonical (Normative)
Convenient (Practical)
The canonical publication point for finalized RFCs. If a protocol is standardized as an RFC, the RFC Editor text is the normative final reference. Published by the IETF, IRTF, IAB, and independent stream.
Related Specs
This is the core contract of every web API, browser request, and server response. You can't design or debug HTTP without knowing this.
HTTP/1.1 is still the baseline. Load balancers, proxies, and debugging tools often present HTTP in this format. Understanding the wire format is essential.