Getting Started with cURL
If you are learning backend development, APIs, or even basic web stuff, you will hear one word again and again: cURL.
At first, it may look scary. A black terminal, strange commands, and lots of symbols. But trust me — cURL is much simpler than it looks.
Let’s start with, what is a server?
Before talking about cURL, we need to understand what a server is.
A server is just another computer on the internet.
Its job is to receive requests and send responses.
Examples:
When you open a website, your browser sends a request to a server.
When you log in to an app, the app talks to a server.
When you fetch data from an API, a server sends that data.
So the basic flow is always:
You → Server → You
What is cURL?
cURL is a tool that lets you talk to a server from the terminal.
That’s it.
Instead of using a browser or an app, you use the command line to:
send a request
get a response
Think of cURL as:
a messenger
that sends messages to servers
and shows you their replies
Why do programmers need cURL?
Browsers hide a lot of things from us.
As a programmer, you often want to:
test an API quickly
see raw data from a server
check if an endpoint is working
debug backend issues
cURL helps because:
it is fast
it works everywhere
it shows the real response from the server
it does not hide errors
Most backend developers use cURL daily.
Making your first request using cURL
Let’s start with the simplest command possible.
curl https://example.com
What happens here?
cURL sends a request to
example.comThe server replies
cURL prints the response in the terminal
This is similar to opening a website in a browser, but instead of a webpage view, you see the raw response.
Understanding request and response
Every server communication has two parts:
1. Request
This is what you send to the server.
It includes:
where you are sending the request (URL)
what you want (GET or POST)
sometimes data (like form data or JSON)
2. Response
This is what the server sends back.
It usually includes:
status code (like 200 or 404)
data (HTML, JSON, text, etc.)
Example idea:
Request: “Hey server, give me this data”
Response: “Here you go” or “Sorry, not found”
GET and POST
To keep things simple, we will talk about only GET and POST.
GET
Used to fetch data
Default method in cURL
Example:
curl https://api.example.com/users
This means:
“Server, please send me the users”
POST
Used to send data to the server
Common for forms, login, signup, etc.
Example (simple idea):
curl -X POST https://api.example.com/login
This means:
“Server, I want to send some data”
Don’t worry about flags too much right now. The goal is to understand the idea, not memorize commands.
Using cURL to talk to APIs
An API is just a server that talks in data (mostly JSON).
With cURL, you can:
call an API endpoint
see the response data
check errors easily
Example:
curl https://api.example.com/posts
You may see something like:
[
{ "id": 1, "title": "Hello World" },
{ "id": 2, "title": "Learning cURL" }
]
This is real backend data, without any UI.
Diagram ideas (conceptual)
You can imagine these flows like this:
1. cURL request flow
cURL → Server → Response
2. Browser vs cURL
Browser → Server → HTML + UI
cURL → Server → Raw data
3. Basic HTTP idea
Request (GET/POST) → Server
Server → Status + Data
4. Backend workflow
Client / cURL → API → Database
Note:
cURL is not advanced magic.
It is a simple way to talk to servers directly.