Explanation so, basically it removes all the create and start server code from your app.js and let you focus only on the application logic part. Note: If you see in package.json file you would note this:
"scripts": {
"start": "node ./bin/www"
}this means if you type in terminal npm start then it will automatically start the ./bin/www file.
In a Project, where there’s a Package.json file - To check which version of a particular package is installed run - VERY IMPORTANT
$ npm ls package_name
e.g.
$ npm ls webpack
/home/paul/codes-Lap/React/MERN-Practice-Post-Bootcamp/brad-mern-shopping-list/package.json
The back slashes “\” are actually acting as escape characters before the double quotes.
/home/paul/PAUL/H/Web/R/R-Vid/WIP/Small-MERN-PostBootcamp/Brad-YouTube-MERN/Learn The MERN Stack [3] - Client Setup & Reactstrap-Setting up Proxy-Explains bind(this).webm
In a MERN project, when I have a separate /client directory containing all the client codes - that means somebody need to go into client directory and run < npm install >
But if I want to do it while my terminal is at the root directory / i.e. without cd-ing into client - I just include the below in script section of my package.json in the server
"client-install": "npm install --prefix client",
And run npm client-install
/home/paul/codes-Lap/React/boilerplate/redux-boilerplate-base-counter/src/App.js
https://bytearcher.com/articles/main-property-in-package.json-defines-entry-point/
After finding the directory Node tries a couple of strategies to determining the entry point of the package. The entry point is the file that is to be loaded and its exports object to be returned as the return value of the originating require call. First, Node looks for a package.json file and checks if it contains a main property. It will be used to point a file inside the package directory that will be the entry point. If main property does not exist, then Node tries in order index.js, index.json and index.node.
https://stackoverflow.com/questions/22512992/node-js-package-json-main-parameter
To put it short:
You only need a main parameter in your package.json if the entry point to your package differs from index.js in its root folder. For example, people often put the entry point to lib/index.js or lib/.js, in this case the corresponding script must be described as main in package.json. You can't have two scripts as main, simply because the entry point require('yourpackagename') must be defined unambiguously.