Context API

Summary

React's built-in way to pass data deeply through the component tree without manually threading props through every intermediate component — commonly used for auth state, theme, or user data in a full-stack app.

• 1Build an auth context storing the current logged-in user, accessible anywhere in the app.
• 2Learn that context updates re-render every consumer — use it thoughtfully for frequently changing data.
• 3Compare Context to prop drilling for a concrete example.