GZIP File Format
`.gz` files, HTTP Content-Encoding: gzip, and tarball distribution (`.tar.gz`) all depend on this format. Know header vs raw DEFLATE stream.
What It Defines
Single-file compression wrapper around DEFLATE: 10-byte header (magic `1F 8B`, method, flags, mtime), compressed blocks, 8-byte CRC32+ISIZE trailer. MIME type: `application/gzip`. Distinct from ZIP (multi-file archive).
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
ZIP is everywhere — downloads, backups, Java JARs, Office Open XML. Central-directory-at-end structure, path traversal (`../../`), and zip bombs are critical security concerns.
Docker layers, npm pack, Linux package sources, and backup workflows use tar. ustar and PAX extensions define long filenames and metadata.
This is the core contract of every web API, browser request, and server response. You can't design or debug HTTP without knowing this.