NPM is a package manager, you can install node.js packages using NPM
NPX is a tool to execute node.js packages.
It doesn't matter whether you installed that package globally or locally. NPX will temporarily install it and run it. NPM also can run packages if you configure a package.json file and include it in the script section.
So remember this, if you want to check/run a node package quickly without installing locally or globally use NPX.
npM - Manager
npX - Execute - easy to remember