Creating Routes and Handling Requests with Express

The first time I created a server using pure Node.js… it felt cool.
But also… a little painful.

I had code like this:

const http = require("http");

const server = http.createServer((req, res) => {
  if (req.url === "/") {
    res.end("Home");
  }

  else if (req.url === "/about") {
    res.end("About");
  }
});

server.listen(3000);

And honestly… even for two routes, it already started looking messy.

Then I imagined:

What if my app had 50 routes?
APIs?
Authentication?
Middleware?

That’s when I understood why developers use:

Express.js

Because Express doesn’t replace Node.js.

It makes Node.js easier.

And honestly…
that’s the reason it became one of the most popular backend frameworks ever.

---

What is Express.js?

Express is a lightweight web framework built on top of Node.js.

Think of it like this:

Node.js = engine

Express = easier control system

Node.js gives you raw backend power. Express gives you cleaner tools to use that power.

---

Why Express Exists

Technically… you CAN create servers using only Node.js. But raw Node.js becomes repetitive very quickly.

You manually handle:

• routes

• headers

• request parsing

• responses

• status codes

Again and again. Express simplifies all of this.

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Raw Node.js vs Express

This comparison made everything click for me.

---

Raw Node.js

if (req.url === "/about") {
  res.end("About");
}

---

Express

app.get("/about", (req, res) => {
  res.send("About");
});

Cleaner.
Readable.
Much easier to scale.

And this is why developers loved Express.

---

Installing Express

First, create a project folder.

Then initialize Node project:

npm init -y

Now install Express:

npm install express

This downloads Express into your project.

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Creating the First Express Server

Create:

app.js

Inside it:

const express = require("express");

const app = express();

app.listen(3000);

Run:

node app.js

And boom. Your Express server is running.

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But What Is express()?

This confused me initially.

const app = express();

This creates an Express application.

You can think of app as: your backend application controller.
Everything happens through it.

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What Are Routes?

Routes are basically: rules for handling requests.

Example:

If user visits "/"
      ↓
run this function

That function is called:

Route Handler

---

Handling Your First GET Request

Now let’s create a route.

app.get("/", (req, res) => {
  res.send("Hello Express");
});

---

What’s Happening Here?

This line:

app.get()

means: handle GET requests.

And:

"/"

means homepage route.

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Understanding req and res

This is SUPER important.

(req, res)

These are objects provided by Express.

---

req

Represents: incoming request

Contains:

• URL

• headers

• body

• query params

Basically: information sent by client.

---

res

Represents: response you send back.

You use it to:

• send data

• send JSON

• send status codes

• end request

---

Real Mental Model

Browser Request
       ↓
Express Route
       ↓
Route Handler Runs
       ↓
Response Sent Back

That’s backend routing.

---

Testing the Route

Run server:

node app.js

Visit:

http://localhost:3000

Output:

Hello Express

And honestly… this simplicity is why Express became so popular.

---

Multiple Routes

Now things become interesting.

app.get("/", (req, res) => {
  res.send("Home Page");
});

app.get("/about", (req, res) => {
  res.send("About Page");
});

Now:

/           → Home Page
/about      → About Page

Different URLs. Different responses.

---

This Is Routing

Express checks: which route was requested
Then runs matching handler.

Simple.
But powerful.

---

Why Routing Matters

Imagine websites without routes. Everything would exist on one page. No structure. Routes organize backend behavior.

They help apps decide: what happens for each request.

---

Handling POST Requests

GET requests are mostly used for: fetching data

POST requests are usually used for: sending data

Example:

• login forms

• signup forms

• creating posts

---

Basic POST Route

app.post("/login", (req, res) => {
  res.send("Login Successful");
});

Now Express handles POST requests for /login.

---

Difference Between GET and POST

This is important.

---

GET

Used for: requesting data

Example:

Get products
Get users
Get homepage

---

POST

Used for: sending data to server

Example:

Login form
Register user
Create blog post

---

Sending Responses

Express makes responses very easy.

---

Sending Text

res.send("Hello");

---

Sending JSON

res.json({
  name: "Nausheen",
});

Output:

{
  "name": "Nausheen"
}

---

Why Express Feels Beginner-Friendly

This is what stood out to me initially. Raw Node.js feels low-level. Express feels readable.
You spend less time managing technical complexity… and more time building features.

---

Express Routing Visualization

Incoming Request
        ↓
Express Checks Route
        ↓
Matching Route Handler
        ↓
Response Returned

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Another Small But Important Insight

Express is still Node.js underneath. This is important.

People often think: “Express replaced Node.js.”

No.
Express RUNS on Node.js. Without Node.js… Express cannot exist.

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Common Beginner Confusion

People often think:

app.get()

creates pages automatically. Not exactly.

It simply defines: what happens when a route is visited.

The browser still sends requests. Express simply responds.

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Why Developers Loved Express

Express solved a huge problem: backend development complexity.

Instead of manually handling everything…

developers got:

• cleaner routing

• easier request handling

• simpler responses

• better structure

And honestly… that simplicity helped Node.js explode in popularity.

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Assignment Practice

Try these yourself:

1. Create Express server
2. Add / route
3. Add /about route
4. Create POST route
5. Send JSON response
6. Visit routes in browser

Experiment with different paths. That’s where routing truly starts making sense.

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Final Understanding

At first, backend development feels complicated.

Requests.
Responses.
Servers.
Routing.

Everything sounds overwhelming.

But Express simplifies the entire process into something very understandable:

A request comes in
a route matches
a function runs
a response goes back

And honestly… once that flow clicks… backend development starts feeling way less scary.