package.md

Version Numbers:

    5 . 19  . 2
    ^----^----^
major  minor  patch
ver.   ver.   ver.

In package.json:

We don't include 'node_modules' folder in our final package that we publish on GitHub. So when we get a repository from GitHub we usually first have to run 'npm install' in order to download 'node_modules' necessary for that file, which are specified in 'dependencies' object inside 'package.json' file. So we can specify what behavior should 'npm' have when retrieving this dependencies on another machine.

package.json

... "dependencies" : { "module" : "*" => update major, minor, and patch versions "module" : "^x.xx.x" => keep major, but update minor and patch versions "module" : "~x.xx.x" => keep major and minor, but update patch version "module" : "x.xx.x" => keep major, minor, and patch versions }

( ^ is carrot symbol and ~ is tilde symbol)

package-lock.json

This file is for managing the dependencies of your dependencies specified in package.json.