What is component in react JS?

Answer 1

A ReactJS component is a modular piece of a webpage. Think of how you can break a page down into different functional pieces. Here's an example of a GitHub page. Different components are labeled in different colors to highlight reusability.

https://imgur.com/KeNcEYs

The modularity and reusability of components is part of the power of React. It allows great code reusability!

Here's a CodePen you can explore to see and play with the code:

https://codepen.io/larobertson/project/editor/ArWpQa

And here's that broken down visually:

https://imgur.com/ckOLaik

I hope this explains it. Here's a resource that talks more about it and other React basics:

https://medium.freecodecamp.org/everything-you-need-to-know-about-react-eaedf53238c4