Getting Started with cURL
What is a server, and why do we need to talk to it?
Before understanding cURL, we need to understand one simple thing.
What is a server?
A server is just another computer.
Its job is to:
wait for requests
process them
send back responses
When you open a website, log in to an app, or fetch data from an API, you are talking to a server.
Normally, your browser does this talking for you.
But programmers often want to talk to servers directly.
That is where cURL comes in.
What is cURL?
cURL is a tool that lets you send messages to a server from the terminal.
Think of it like this:
Browser: talks to servers using buttons and screens
cURL: talks to servers using commands
Both do the same thing.
cURL just removes the UI and gives you full control.
Why do programmers need cURL?
cURL is useful because it helps you:
test APIs without writing code
debug backend issues quickly
understand what is actually sent over the network
automate requests in scripts
work without a browser
High-level flow: cURL talking to a server
Simple.
You send a request.
The server sends a response.
Making your first cURL request
Let us start with the simplest possible example.
curl https://example.com
That is it.
What just happened?
cURL sent a request to
example.comThe server responded with data
cURL printed that data in your terminal
In this case, the data is HTML.
Understanding request and response
Whenever you use cURL, two things are involved.
1. The request
This is what you send to the server.
It includes:
where you want to go (URL)
what you want (GET, POST, PUT, DELETE)
2. The response
This is what the server sends back.
It includes:
status (did it work or not?)
data (HTML, JSON, text)
Introducing GET and POST
GET request
Used when you want to fetch data.
Example:
curl https://api.example.com/users
Meaning:
“Hey server, give me the users.”
POST request
Used when you want to send data.
Example:
curl -X POST https://api.example.com/users
Meaning:
“Hey server, I want to create something.”
That is enough to get started.
Using cURL to talk to APIs
APIs are just servers that expect structured requests.
Example API request:
curl https://jsonplaceholder.typicode.com/posts/1
Response:
Status code (like 200)
JSON data
This is exactly how backend services talk to each other.
cURL lets you simulate that conversation.
Where cURL fits in backend development
cURL sits next to your backend.
It helps you test and debug without any frontend involved.
This is why backend engineers rely on it daily.
Common mistakes beginners make with cURL
1. Fear of the terminal
cURL looks scary because it lives in the terminal.
In reality, it is simpler than many GUIs.
2. Copying complex commands too early
Avoid huge commands with many flags in the beginning.
Start simple.
Understand first.
3. Not reading the response
The response is the whole point.
Always look at:
status
returned data
4. Assuming cURL is only for APIs
cURL can fetch websites, images, files, and more.
APIs are just one use case.
