Basics about Backend

Backend has 2 major components:-
1. A Programming Language:- Java, javascript, php, golang, c++ etc. ( Almost all these languages use some framework or library).
2. A Database:- Mongo, MySQL, Postgres, sqlite etc. (Similarly, you will use an ORM (Object-Relational Mapping) or ODM (Object Document Mapping) when interacting with databases. Names like Prisma and Mongoose will come up).

Frontend (Browser and Mobile):Users interact with the application through the browser or mobile app.

API (Application Programming Interface):Acts as an intermediary, allowing the frontend to communicate with the backend server.

Backend:Processes requests from the frontend, interacts with the database, and sends responses back.
Contains the logic and functions needed to handle specific tasks like user authentication.

Database:Stores application data and is located in another continent for better performance and redundancy.

When dealing with backend development, you primarily handle three types of tasks:

1.Data Handling:

The most common task in backend development is processing data received from the frontend.
Example: When a user tries to log in, the frontend sends the username and password to the backend. The backend verifies these credentials against the database and sends a response back to the frontend.

2.File Handling:

Backends often need to handle file uploads and downloads. This can include storing files on the server or retrieving them for user access.
Example: A user uploads a profile picture. The backend saves this image to the server and updates the user's profile to reference the uploaded file.

3.Third-Party API Integration:

Backends frequently interact with third-party services to extend functionality.
Example: To send an email confirmation, the backend may use an email service provider's API. The backend sends the necessary data (recipient email, subject, message body) to the third-party API, which then handles the email sending.

In modern JavaScript environments, there are several options for backend development beyond the traditional Node.js. Here are the key points:

Multiple Runtime Environments:

Historically, learning backend development in JavaScript often started with Node.js.
Nowadays, there are alternative runtime environments like Deno and Bun.
You can even mix environments, using part of your backend on Node.js and part on Deno or Bun.

The file structure I am referring to is a common organization pattern used in backend development, regardless of the specific programming language or framework. Here's a breakdown of the typical components based on the content you provided:

1. Root Directory

index.js or main.js: This is the entry point of your application. It’s where you initialize and start your application, connect to the database, and set up basic configurations.

2. Folders and Files

app.js:This file typically contains the main application logic and configuration settings, such as middleware setup, routes configuration, and application-level settings.

config/:

Configuration Files:These files include environment-specific settings such as database connections, API keys, and other constants.
Example: config.js, databaseConfig.js.

constants/:

constants.js:Contains immutable values or configurations used throughout the application. This can include things like status codes, roles, or types. For instance, if you're building a booking application, constants might include seat types (e.g., window, middle, aisle).

models/:

Model Definitions:Defines the schema for the data stored in your database. This is where you set up how your data is structured and validated.
Example:userModel.js, productModel.js.

controllers/:

Controller Logic: Contains functions or methods that handle business logic. Controllers manage the requests and responses, processing data and interacting with models.
Example: userController.js, productController.js.

routes/:

Routing Definitions:Maps URLs to specific controller actions. This determines how different HTTP requests (GET, POST, etc.) are routed to the appropriate controllers.
Example:userRoutes.js, productRoutes.js.

middlewares/:

Middleware Functions:Contains functions that execute during the request-response cycle, such as authentication checks, logging, or data validation.
Example: authMiddleware.js, errorHandlingMiddleware.js.

utils/:

Utility Functions: Houses reusable functions or helpers used across the application, such as email sending functions or file upload handlers.
ExampleemailHelper.js, fileUploadHelper.js.

database/:

Database Initialization:Contains scripts or configurations related to database setup and connections.
Example:dbConnection.js, dbSetup.js.

`views`/ (if applicable):

Template Files:Used if the application includes server-side rendering. This directory contains the view templates or files used to generate HTML content.
Example: index.ejs, userProfile.ejs.

3. Other Files

package.json: Manages dependencies and scripts for the project.
.env: Stores environment variables like database credentials or API keys.
.gitignore: Specifies which files and directories should be ignored by version control