Web, backend & deployment

Frontend — What runs in the browser (or app): HTML, CSS, JavaScript, React, etc. Users see and click this.

Backend — Code and services that run on a server (or serverless functions): business logic, auth checks, talking to a database.

API — A defined way for programs to talk: “call this URL with this JSON, get this response.” REST and GraphQL are common styles.

Database — Durable storage for structured data (users, posts). SQL databases use tables; NoSQL is a bucket term for other shapes.

Environment variables — Secret or config values (API keys, database URLs) kept out of source code and injected at runtime.

DNS — Maps human names (ai.example.com) to servers. You set records at your domain registrar or DNS host.

SSL / TLS / HTTPS — Encrypted HTTP. Browsers expect HTTPS for anything serious; certificates are usually auto-issued by hosts like Vercel.

CDN — Network that caches static files near users for speed.

Serverless — You upload code; the platform runs it per request without you managing a long-lived server (tradeoffs: cold starts, limits).

Container / Docker — Packages app + dependencies so it runs the same everywhere; common in larger teams, optional for many small apps.

Monorepo — One Git repo holding multiple packages or apps; not required for solo projects.

CI/CD — Automated build, test, deploy when you push code (e.g. GitHub Actions → Vercel).