It lets you perform any necessary building/prep tasks for your project, prior to it being used in another project. npm build is an internal command and is called by link and install commands, according to the documentation for build: This is the plumbing command called by npm link and npm install.

What is the use of build in react?

When a user visits your site, each of your files will require an additional HTTP request, making your site slower to load. So to remedy this, you can create a “build” of our app, which merges all your CSS files into one file, and does the same with your JavaScript.

What is build folder in react?

When we run npm run build , we see output in /build folder. npm run build. Builds the app for production to the build folder. It correctly bundles React in production mode and optimizes the build for the best performance. The build is minified and the filenames include the hashes.