Glossary

Term	What it means
App Router	Next.js routing based on the app/ directory. All projects use App Router — never Pages Router.
Server Component	React component that runs ONLY on the server. Can be async, fetch data directly, never exposes secrets.
Client Component	"use client" at the top. Runs in the browser. Required for useState, useEffect, event handlers, browser APIs.
Server Action	Async function marked "use server". Called like a regular function but runs on the server. Safe way to mutate data.
PPR (Partial Prerendering)	Static shell of a page prebuilt at build time; dynamic sections stream at request time. Stable in Next.js 16.
after()	Next.js 16 API to run code AFTER the response is sent. For analytics and audit logs.
revalidatePath()	Tells Next.js to purge cached data for a URL, triggering a fresh fetch on next visit.
Drizzle Schema	TypeScript code in lib/db/schema.ts defining your DB tables. Source of truth for your data model.
Migration	SQL file describing a DB structure change. Generated by drizzle-kit generate; applied by drizzle-kit migrate.
CI/CD	Continuous Integration / Continuous Deployment. Automated pipelines that run tests and deploy on every push. Included in the capstone repo but not required for this program.
PR / Pull Request	Request to merge your branch into main. Forum for code review, discussion, automated checks.
Squash and Merge	Combining all PR commits into one before merging. Keeps main history clean.
Rebase	Replaying your commits on top of latest main. Keeps branch up to date without a merge commit.
Conventional Commits	Commit message format: type(scope): description. e.g., feat(tasks): add drag-and-drop.
useOptimistic()	React 19 hook. Instantly updates UI to show expected result before server confirms.
useActionState()	React 19 hook. Wires a form to a Server Action and exposes pending/error/result state.
useFormStatus()	React 19 hook. Used inside a form to access submission pending state.
Zod	TypeScript schema validation library. Use in every Server Action. Never trust client input.
Biome	Rust-based tool replacing ESLint + Prettier. Lint and format in one fast command.
Vitest	Primary test runner. Similar API to Jest but faster and natively ESM-compatible.
Turbopack	Rust-based dev bundler built into Next.js 16. Much faster than Webpack for local development.
Neon	Serverless Postgres provider. Free tier. Supports HTTP driver for Edge Runtime.
ProjectFlow	The capstone project — a Kanban-style project management tool like Trello or Asana.
Upstream	The original capstone repo you forked from. Add as a git remote to pull in mentor updates.
forbidden()	Next.js 16 helper for logged-in users who lack permission. Returns HTTP 403.
unauthorized()	Next.js 16 helper for unauthenticated users. Returns HTTP 401.