Data Formats

Contents

Data Formats#

Wire and config plumbing, plus the markup and styling formats that share the same parsing-and-emitting workflow. JSON for an API response, YAML for a config, Parquet on disk in an analysis estate, HTML for a phished page, CSS for the theme on top. Reading and writing these on the way to and from a target is a unit-level skill.

These are not programming languages (no control flow, no execution), but identifying a format on sight and parsing it at the command line moves the work forward on every job.

Data#

Structured serialisation. Wire payloads, configs, columnar storage.

JSON

The format parsed on every collection. REST APIs, audit logs, telemetry, manifests.

JSON
YAML

Human-friendly serialisation. Indentation, comments, anchors. Every JSON document is also valid YAML.

YAML
TOML

Modern config format with a real spec. pyproject.toml, Cargo.toml. Typed values, dates first-class, explicit sections.

TOML
INI

The longest-living config format. No standard; many dialects (configparser, systemd, Git config, my.cnf, pip.conf, php.ini).

INI
XML

The older sibling of JSON. Schemas, XPath, XSLT. Embedded in finance, healthcare, document formats.

XML
CSV

Comma-Separated Values. The simplest tabular format and the one that outlives most replacements.

CSV
TSV

Tab-Separated Values. The underrated cousin of CSV; the tab almost never appears inside real data.

TSV
ProtoBuf

Google’s compact binary serialisation. Schema-backed, typed bytes; not human-readable.

ProtoBuf
Parquet

Columnar binary format for analytical workloads. The storage format under nearly every data lake.

Parquet
HDF5

Binary container for large, heterogeneous numerical datasets.

HDF5
OpenAPI

Specification document (YAML or JSON) describing HTTP APIs. Endpoints, request and response schemas, auth.

OpenAPI

Markup#

Tags around content. The document and web layer.

HTML

The document format of the web. Living standard maintained by WHATWG.

HTML

Styling#

Presentation rules layered on top of markup.

CSS

How HTML looks. Layout, animation, theming, selection.

CSS
SCSS

CSS preprocessor with CSS-superset syntax. Variables, nesting, mixins, modules.

SCSS
LESS

CSS preprocessor with variables, nesting, mixins, functions. Compiles to plain CSS.

LESS