All about Package.json ?

Usually, when we are going to start development with any Javascript Framework related project, Package.json is the first step to know all about. And today we will know all about Package.json

What is Package.json?

It's a plain JSON file
Kind of manifest for the project
Help others to easily use, manage and install dependencies
List packages on which project depends on
Packages are in ranges or the specific version
File must contain packages in "name" and "version" format
Used to give information to npm that allows it to identify the project
And help to handle the project's dependencies
Also contain other metadata such as license, distribution, configuration data
Also recommended to put DevDependencies, which makes dev life smooth by fast development

Package.json contains?

All the information are listed in ascending order as below:

name
 sets the application/package name
version
indicates the current version
description 
is a brief description of the app/package
main
set the entry point for the application
private
if set to true prevents the app/package to be accidentally published on npm
scripts
defines a set of node scripts you can run
dependencies
 sets a list of npm packages installed as dependencies
devDependencies
 sets a list of npm packages installed as development dependencies
engines
sets which versions of Node this package/app works on
browserslist
is used to tell which browsers (and their versions) you want to support


Role of package.json?

Whenever user run "npm install" command on root level, all the dependencies related to project which is listed in Package.json will be installed.
and put all dependencies to "node_modules" directory