NoSQL database using documents (JSON-like). Use Mongoose for schema modeling. CRUD operations: insertOne/Many, find, updateOne/Many, deleteOne/Many. Indexing improves query performance.
Backend framework for Node.js. Create REST APIs with routing, middleware for request processing, error handling, CORS configuration, and authentication with JWT.
Build UI with components, manage state with hooks, fetch data with axios or fetch API, handle forms, implement routing with react-router-dom.
JavaScript runtime for server-side code. Handle async operations, file system access, environment variables with dotenv, process management with PM2.
Connect React frontend to Express backend via API calls. Handle authentication with JWT tokens, manage CORS, deploy frontend (Vercel/Netlify) and backend (Heroku/Railway) separately or together.