Suggest an editImprove this articleRefine the answer for “What is HTTP?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**HTTP (HyperText Transfer Protocol)** is an application-layer protocol used to exchange data between a client and a server over the internet. **Key point:** HTTP is a stateless protocol: the server does not store the client's state, every request is independent, and all the necessary information is passed in that request.Shown above the full answer for quick recall.Answer (EN)Image**HTTP (HyperText Transfer Protocol)** is an **application-layer protocol** used to **exchange data between a client and a server over the internet**. In simpler terms: **HTTP is a set of rules that let a browser and a server "talk" to each other**. --- ## Why HTTP is needed HTTP is needed so that: - a browser can **request a web page** - a server can **send a response** - the client and the server **understand each other** Without HTTP, a browser would not know: - how to ask for a page - how the server should respond - how to tell whether the request succeeded --- ## Where HTTP is used HTTP is used almost everywhere: - when opening websites - in REST APIs - in mobile applications - when services exchange data with each other Every time you: - visit a site - click a button - submit a form , HTTP is at work. --- ## How HTTP works (simplified) 1. A client (for example, a browser) sends an **HTTP request** 2. The server accepts the request 3. The server processes it 4. The server sends an **HTTP response** 5. The client receives and uses the result The model is always the same: **request, response** --- ## What data is transferred over HTTP HTTP can transfer: - HTML pages - JSON and XML - images - files - form data HTTP **does not care what exactly is being transferred**, it just delivers the data. --- ## Important properties of HTTP ### 1. Application layer HTTP runs at the **application layer of the OSI model** and relies on the lower layers (TCP/IP) to deliver data. --- ### 2. Stateless HTTP is a **stateless protocol**: - the server does not store the client's state - every request is independent - all the necessary information is passed in the request --- ### 3. Text-based and readable HTTP requests and responses: - have a clear structure - are easy to read and debug - are convenient for development and testing --- ## A real-life example When you type in a site's address: - the browser sends an HTTP request: "give me the page" - the server replies with an HTTP response: "here is the page and status 200 OK" - the browser shows the page to the user --- ## Short answer for an interview Remember this phrasing: > **HTTP is an application-layer protocol that defines the rules for exchanging data between a client and a server, and it is used to transfer web pages and API requests over the internet.**For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.