npm the package manager
npm is a couple of things. First and foremost, it is an online repository for the publishing of open-source Node.js projects.
Second, it is a CLI tool that aids you install those packages and manage their versions and dependencies. There are hundreds of thousands of Node.js libraries and applications on npm and many more are added every day.
npm by itself doesn’t run any packages. If you want to run a package using npm, you must specify that package in your
npx the package runner
Since npm version 5.2.0 npx is pre-bundled with npm. So it’s pretty much a standard nowadays.
npx is also a CLI tool whose purpose is to make it easy to install and manage dependencies hosted in the npm registry.
It’s now very easy to run any sort of Node.js based executable that you would normally install via npm.