# HTTP (Hypertext Transfer Protocol)

URL: https://softwaredictionary.org/terms/http
Category: Web Development
Last updated: 2026-09-29

In short: HTTP is the protocol that browsers, apps, and servers use to exchange web pages and data through a simple cycle of requests and responses.

## What is HTTP?

HTTP defines how a client, such as a browser or mobile app, asks a server for something and how the server replies. Every exchange is a request followed by a response, and each message is made of a start line, headers that carry metadata, and an optional body with the actual content.

A request names a method that describes the intended action, such as `GET` to read data, `POST` to create it, `PUT` or `PATCH` to update it, and `DELETE` to remove it. The response includes a status code that summarizes the result: `200` means success, `404` means not found, and `500` means the server hit an error.

HTTP is stateless, meaning each request stands alone and the server does not automatically remember earlier ones. Cookies and tokens are layered on top to keep users logged in. The protocol has evolved from HTTP/1.1 to HTTP/2 and HTTP/3, which move data more efficiently but keep the same methods, headers, and status codes.

HTTP is often confused with HTTPS. HTTPS is the same protocol sent through an encrypted TLS connection, so outsiders cannot read or tamper with the traffic; plain HTTP sends everything as readable text and should not be used for real websites.

## Key takeaways

- HTTP works as a series of requests and responses.
- Methods like `GET` and `POST` describe the requested action.
- Status codes like `200` and `404` summarize the result.
- HTTP is stateless; cookies and tokens add memory between requests.
- HTTPS is HTTP over an encrypted connection.

## Example: A raw HTTP request and response

```http
# Request sent by the client
GET /users/42 HTTP/1.1
Host: api.example.com
Accept: application/json

# Response sent back by the server
HTTP/1.1 200 OK
Content-Type: application/json

{"id": 42, "name": "Ada"}
```

## Frequently asked questions

**What is the difference between HTTP and HTTPS?**

HTTPS is HTTP sent over an encrypted TLS connection. It protects data from being read or modified in transit and proves to the browser that it is talking to the real website.

**What does it mean that HTTP is stateless?**

It means the server treats every request independently and does not remember earlier requests on its own. Applications use cookies, sessions, or tokens to recognize returning users.

**What is the difference between GET and POST?**

`GET` asks the server to return data and should not change anything, while `POST` sends data in the request body to create something or trigger an action.

## Sources

- [RFC 9110: HTTP Semantics](https://www.rfc-editor.org/rfc/rfc9110.html)
- [RFC 9112: HTTP/1.1](https://www.rfc-editor.org/rfc/rfc9112.html)
- [MDN: Overview of HTTP](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Overview)

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Software Dictionary: https://softwaredictionary.org/ · https://softwaredictionary.org/llms.txt