Learn · Web development
An API (application programming interface) is a defined way for two pieces of software to talk to each other. It's the messenger that takes a request, tells another system what you want, and brings back the response. When a site shows live weather or takes a card payment, it's calling an API.
Think of it like a restaurant menu. You don't go into the kitchen. You order from a set list, and the kitchen returns your dish. An API is that menu: it defines what you can ask for and what you'll get back, hiding the complexity behind it.
APIs are how modern software connects. They let your site use maps, payments, email, and AI without building any of those from scratch, and they let your own systems share data with each other securely.
Updated July 2026
Related
The frontend is everything the user sees and interacts with in the browser: layout, buttons, text, and animations. The backend is the server side the user never sees: the database, the business logic, and the code that decides what data to send. Frontend is the storefront, backend is the warehouse.
A database is organized storage for a site's data: users, orders, posts, settings, anything that needs to be saved and retrieved. It lets an application find, add, update, and relate information quickly and reliably. Any site with accounts or saved content sits on a database.
When you type an address, your browser asks a server for that page, the server sends back files (HTML for structure, CSS for style, JavaScript for behavior), and the browser assembles them into what you see. The whole exchange usually takes under a second and repeats every time you click.