React
Props
Data passed from a parent component into a child component, like arguments into a function.
Reviewed by the RadarTrek editorial team · June 2026
Props ("properties") are how a parent component passes data down to a child component — a title to display, a colour, a click handler. A component receives props as a single object and uses them to render itself, but cannot change the props it receives; data flows one way, down the tree.
Why it matters
- —Props are how components stay reusable — the same Button component renders differently based on its props.
- —Props flow one direction (parent to child), which keeps data flow predictable and easy to trace.
- —Confusing props (passed in) with state (managed internally) is the most common early React mix-up.
Where to learn this
🎓
Props: Passing Data Down
React Fundamentals course
This is the exact lesson that covers this term in depth — with examples, diagrams, and a hands-on exercise.