How to setup Node js project?

1. Install Node.js
   • First, visit the Node.js official website.
   • Download and install the setup node js project based on your system (Windows, Mac, etc.).
2. Initialize the Project

Run the following command in your terminal:

npm init

• Press Enter multiple times and then type yes to complete the process.
• This will create a package.json file inside your project.

3. What is package.json?
   • This file is generated by npm (Node Package Manager).
   • It contains an object called dependencies, which lists all installed third-party libraries along with their versions.

Example:

“ts-node”: “^2.3.0”

• The ^ symbol means that when you run npm update, this library will get updated automatically. If you remove this symbol, the version will remain fixed.

Example of package.json

• All installed libraries are listed under the dependencies object.
• There is also a devDependencies object.

What are devDependencies?

• It includes libraries that are only needed during development but are not required in production.

Understanding Development & Production Environments

1. Development Environment
   • Used for testing on a local PC or a testing environment.
   • Example: The database used during testing is different from the one used by the public.
2. Production Environment
   • This is the live environment used by actual users.

What is Frontend & Backend?

• When a mobile app or website sends a request (e.g., login request with email and password) to the server, the backend (Node.js) connects to the MongoDB database.
• After fetching data, the server either returns the requested data or an error.

1. Frontend
   • The code running on a mobile app or website.
2. Backend
   • The Node.js code runs on a separate server (not on your local PC).

How Do Frontend & Backend Communicate?

• They communicate using APIs (Application Programming Interface).
• Just like we use a GUI (Graphical User Interface) to interact with a computer or mobile device using buttons,
  applications use APIs to communicate with other applications.

Example:

• You can use Google authentication to log in using a Gmail ID.
• This happens using an API provided by Google.

Conclusion:
A good software is not just popular because it has many users, but also because it allows other applications to interact with it using APIs.