Getting Started with cURL

What is a server and why we talk to it

First basic thing.
A server is just another computer on internet.
This computer stores websites, data, APIs, images, everything.

When we open a website in browser, we are actually talking to a server.
We send request → server sends response.

Browser hides all this.
But sometimes as a developer, we want to talk to server directly.
This is where cURL comes.

What is cURL

cURL is a tool to send request to a server from terminal.

In simple words:
cURL = way to talk to server without browser

Using cURL, we can:

• get data from a website

• send data to an API

• test backend responses

It works using command line (terminal / CMD).

Why programmers need cURL

As a beginner I asked: why not just use browser?

Because cURL helps when:

• we want to test APIs

• we want to see raw response (JSON, text)

• browser is not needed

• frontend is not ready yet

Backend developers use it a lot.
Frontend developers also use it for API testing.

Making your first cURL request

This is the simplest command.

curl https://example.com

What happens?

• cURL sends a request to example.com

• server sends HTML response

• terminal prints the response

It feels like magic first time

Understanding request and response

Every communication has two parts.

Request

What we send to server:

• URL

• method (GET, POST)

• sometimes data

Response

What server sends back:

• status code (200, 404, 500)

• data (HTML, JSON, text)

Simple flow diagram

You (cURL)
   |
   |  Request
   v
 Server
   |
   |  Response
   v
 Terminal output

Browser request vs cURL request

Both do same job but look different.

Browser:
Click URL → Browser → Server → Page UI

cURL:
Command → Terminal → Server → Raw data

Browser shows UI.
cURL shows raw response.

Using cURL to talk to APIs

APIs mostly return JSON data.

Example:

curl https://api.example.com/users

Response might look like:

[
  { "name": "Aman", "age": 22 },
  { "name": "Riya", "age": 21 }
]

This is very useful to check:

• API is working or not

• data structure

GET and POST

GET

Used to get data.

curl https://api.example.com/posts

POST

Used to send data.

curl -X POST https://api.example.com/login

For now, just remember:

• GET = ask something

• POST = send something

No need to remember all flags now.

Common mistakes beginners make with cURL

I also did these mistakes

• Forgetting https://

• Copying long commands without understanding

• Panicking when response is too long

• Thinking error means cURL is broken

Errors are normal.
They actually help learning.

Where cURL fits in backend learning

Frontend (HTML/CSS/JS)
        |
        v
      API
        |
        v
      Server
        ^
        |
      cURL

cURL helps us understand:

• how frontend talks to backend

• how APIs behave

• what server actually returns

Short Summary

cURL is a simple tool to talk to servers using terminal.
It helps developers test websites and APIs without browser.
As a beginner, start with small GET requests.
Do not fear terminal. Practice slowly.
cURL is optional, but very powerful when you understand basics.