HTTP Semantics
This is the core contract of every web API, browser request, and server response. You can't design or debug HTTP without knowing this.
What It Defines
The foundational HTTP spec. Defines methods (GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS), status codes (1xx-5xx), headers, content negotiation, conditional requests, range requests, and the https URI scheme.
Canonical (Normative)
Convenient (Practical)
Related References
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
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.
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.
HTTP/3 is the current performance frontier for web delivery. CDNs enable it automatically; understand it for performance tuning and debugging.
Every HTTPS connection, SMTP/IMAP over TLS, OAuth token exchange, and API call uses TLS. It is the foundational security layer.