// Install as a dependency
npm install --save packageName
// OR
npm install --save package1 package2
// OR
npm install --save package@version
// OR
npm i -s packageName

// Install as a dev-dependency
npm install --save-dev package@version
// OR
npm i -D packageName

//Install globally
npm install --global packageName
//OR
npm i -g packageName

// You might need SU access on macos/linux to install globally