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Backend Fundamentals in Node.js

Understand what a backend is, how backend systems work conceptually, and how Node.js fits into the backend ecosystem.

Backend Basics

This lesson establishes what a backend is and what responsibilities it has in a software system.

1. What Is a Backend

Backend as a system, not just code.

2. Backend Responsibilities

What problems backend systems solve.

Frontend and Backend Boundary

Clear boundaries between frontend and backend are critical for secure and maintainable systems.

1. Role of Frontend

What frontend is responsible for.

2. Role of Backend

What backend is responsible for.

Client–Server Model

Most backend systems follow the client–server communication model.

1. Client

Who initiates communication.

2. Server

Who responds to requests.

Request–Response Flow

Understanding this flow is essential before writing APIs.

1. Request Phase

What happens when a request arrives.

2. Response Phase

How a backend sends results.

State Management

State handling has major impact on scalability and reliability.

1. Stateful Systems

Systems that remember information.

2. Stateless Systems

Systems that do not store request context.

Node.js in Backend Context

Node.js provides the runtime required to build backend services using JavaScript.

1. Node.js Runtime

What Node.js provides.

2. Non-blocking Execution

Why Node.js scales well.