Glossary
What the words on this site mean — one line each, with a link to the people who define them.
This site explains itself in public. The credits name every piece of technology behind it, the notes argue about browser bugs, and the conformance claim cites clauses by number — so a reader who follows any of that meets words that are precise and unfamiliar at the same time.
Each one below gets a line. The name links to the people who define it, because a summary is a place to start and a specification is the thing that is true.
- accessibility
- a site's fitness for people with disabilities
- ACME
- the protocol that issues a certificate without a human
- Ansible
- a tool that puts a server into a written-down state
- ArcGIS
- Esri's commercial GIS platform
- ARIA
- extra markup that names a control for assistive tech
- authentication
- proof that a request is from who it claims
- AWS
- Amazon's cloud platform
- axe
- the accessibility engine this site is audited with
- Azure
- Microsoft's cloud platform
- backup
- a copy of data against loss, and the making of it
- Bash
- the GNU shell most scripts are written for
- Bicep
- Azure's own language for declaring infrastructure
- BigQuery
- Google's warehouse for querying very large tables
- cache
- a stored copy a browser may reuse instead of asking
- canonical URL
- the one address a page says is its own
- CDN
- servers near the reader that hand out copies
- cloud
- computing rented by the hour from somebody else
- container runtime
- the program that actually starts a container
- Content Security Policy
- a list of where a page may load things from
- contrast ratio
- how far apart two colours are, as a number
- cookie
- a small value a site asks the browser to keep
- Core Web Vitals
- three measurements of how a page feels to use
- crawler
- a program that fetches pages to index them
- CSS
- the language that says how a page looks
- CTE
- a named subquery a bigger query reads as a table
- daemon
- a program that runs in the background, unattended
- Django
- a Python framework for building web applications
- DNS
- the directory turning a name into an address
- Docker
- a way to ship a program with everything it needs
- encryption
- making data unreadable without the key
- ESLint
- a rule-driven linter for JavaScript
- favicon
- the small picture a browser shows beside a page
- feed
- a page's updates, in a format you subscribe to
- firewall
- the rule set that decides which traffic passes
- font
- a typeface in a file the page downloads
- GDAL
- the library that reads every geospatial format
- gemtext
- a text format with one link per line
- GeoJSON
- geography written as JSON
- GIS
- systems for data that has a place on a map
- git
- the version control this site's history lives in
- git hook
- a script git runs when something happens
- GitHub
- Microsoft's hosting for git repositories
- GitLab
- a git platform you can also run yourself
- Google Cloud
- Google's cloud platform
- Gopher
- a menu protocol older than the web
- Grafana
- a dashboard tool for metrics and logs
- hardening
- removing what an attacker could use
- hreflang
- the attribute pairing a page with its translations
- HSTS
- a browser's promise to use HTTPS next time
- HTML
- the language a page's structure is written in
- HTTP
- the request and answer the web is built on
- HTTPS
- the same requests, over an encrypted connection
- idempotent
- safe to run twice, because the second time changes nothing
- JavaScript
- the language browsers run
- JSON
- the text format most data travels in
- kernel
- the core of an operating system
- Kubernetes
- a system that keeps a fleet of containers running
- landmark
- a region of a page a screen reader can jump to
- Leaflet
- a small library for maps in a browser
- Lighthouse
- Chrome's own audit of speed, markup and good practice
- Linux
- the kernel most servers run on
- logging
- writing down what happens, as it happens
- macOS
- Apple's desktop operating system
- Mapbox
- a commercial source of map tiles and styles
- Markdown
- plain text with a few marks that mean formatting
- metrics
- numbers a system reports about itself
- nginx
- a web server and reverse proxy
- onion service
- an address that works only through Tor
- OpenAPI
- a machine-readable description of an HTTP API
- OpenTelemetry
- one vendor-free way to send telemetry
- partitioning
- splitting one table into physical pieces
- PHP
- the language most of the old web runs on
- Playwright
- the tool that drives a browser in tests
- Podman
- a container engine that needs no daemon
- port
- the number that picks a service on a host
- PostGIS
- the extension that gives PostgreSQL geometry
- PostgreSQL
- the database most of this work was built on
- Prometheus
- a database that scrapes and stores metrics
- proxy
- a server that forwards a request on your behalf
- Python
- the language most of this site's tooling is in
- QGIS
- the free desktop GIS
- RBAC
- permissions granted to a role, not a person
- Redis
- an in-memory store for things that live briefly
- robots.txt
- the file telling crawlers where not to go
- RSS
- one of the two formats a feed is written in
- Ruff
- a fast linter and formatter for Python
- Rust
- a compiled language that checks memory for you
- schema
- a named group of tables inside one database
- screen reader
- software that reads a page aloud, or into braille
- SEO
- making a page findable without paying for it
- service worker
- a script that answers requests when the network cannot
- sitemap
- a list of a site's pages, written for machines
- SQL
- the language relational databases answer
- SQLite
- a whole database in a single file
- SSH
- an encrypted shell on another machine
- static site generator
- a program that writes every page out in advance
- structured data
- facts about a page, written for machines
- stylesheet
- the file that holds a page's CSS
- Subresource Integrity
- a hash a browser checks a file against
- systemd
- the thing that starts everything else on Linux
- TLS
- the handshake that encrypts a connection
- Tor
- a network that routes traffic through volunteer relays
- TypeScript
- JavaScript with types checked before it runs
- Ubuntu
- a Linux distribution common on servers
- URL
- the address that says where a thing is
- viewport
- the part of a page a window actually shows
- VPN
- a private network carried over a public one
- WCAG 2.2
- the accessibility standard this site is held to
- web app manifest
- the file that lets a site be installed
- WebP
- an image format smaller than the ones it replaces
- WordPress
- the CMS most of the web is published with
- YAML
- a format for settings a person can still read
