Skip to main content

What is an API? Application Programming Interfaces Explained

By April 12, 2022February 8th, 2024IT Education

API architecture is usually explained in terms of client and server. The application sending the request is called the client, and the application sending the response is called the server. So in the weather example, the bureau’s weather database is the server, and the mobile app is the client. Because APIs simplify how developers integrate new application components into an existing architecture, they help business and IT teams collaborate. Business needs often change quickly in response to ever shifting digital markets, where new competitors can change a whole industry with a new app. In order to stay competitive, it’s important to support the rapid development and deployment of innovative services.

api meaning

For example, by using’s API, you can request current weather data and display it on your site for visitors. That way visitors can get weather information without having to leave your website and go to In this approach, the server assigns a unique generated value to a first-time client. Whenever the client tries to access resources, it uses the unique API key to verify itself. API keys are less secure because the client has to transmit the key, which makes it vulnerable to network theft.

Twitter API Endpoint Example

Unlike POST, sending the same PUT request multiple times in a RESTful web service gives the same result. Sending the same POST request multiple times has the side effect of creating the same resource multiple times. Clients use GET to access resources that are located at the specified URL on the server. They can cache GET requests and send parameters in the RESTful API request to instruct the server to filter data before sending. In REST architectural style, servers can temporarily extend or customize client functionality by transferring software programming code to the client.

api meaning

This same principle is used on modern mobile operating systems like iOS and Android, where mobile apps have permissions that can be enforced by controlling access to APIs. For example, if a developer tries to access the camera via the camera API, you can deny the permission request and the app has no way of accessing your device’s camera. Webhooks are often referred to as reverse APIs or push APIs, because they put the responsibility of communication on the server, rather than the client. Instead of the client sending HTTP requests—asking for data until the server responds—the server sends the client a single HTTP POST request as soon as the data is available. Despite their nicknames, webhooks are not APIs; they work together.

What is an API Key? (And Are They Secure?)

It provides integration, acceleration, governance, and security for Web API and SOA-based systems. An API defines the interfaces by which one piece of software communicates with another at the source level. In layman’s terms, I’ve always said an API is like a translator between two people who speak different languages. In software, data can be consumed or distributed using an API (or translator) so that two different kinds of software can communicate. Good software has a strong translator (API) that follows rules and protocols for security and data cleanliness.

api meaning

An API is a set of commands, functions, and protocols which programmers can use when building software for a specific OS or any other software. The API allows programmers to use predefined functions to interact with the operating system, instead of writing them from scratch. All computer operating systems, such as Windows, Unix, and the Mac OS and language such as Java provide an application program interface for programmers. The representational state transfer (REST) architecture is perhaps the most popular approach to building APIs. REST relies on a client/server approach that separates front and back ends of the API and provides considerable flexibility in development and implementation. REST is stateless, which means the API stores no data or status between requests.


API Integration is the connection between two or more applications, via APIs, letting you exchange data. It is a medium through which you can share data and communicate with each other by involving APIs to allow web tools to communicate. Due to the rise in cloud-based products, API integration has become very important. While the data transfer will differ depending on the web service being used, the requests and responses all happen through an API. There is no visibility on the user interface, meaning APIs exchange data within the computer or application, and appear to the user as a seamless connection.

API development is an iterative and collaborative process, so it’s important to leverage the appropriate tooling to ensure everything runs as smoothly as possible. It’s also essential for teams to use an API platform that integrates with these tools, which will reduce friction and augment existing workflows. One of the most common reasons developers turn to APIs is to integrate one system with another. A simple way to understand how APIs work is to look at a common example—third-party payment processing. When a user purchases a product on an ecommerce site, they may be prompted to “Pay with Paypal” or another type of third-party system.

  • They are typically a URL exposed by the server that enables other systems to connect to the endpoints.
  • IBM API Connect is also available with other capabilities as part of IBM Cloud Pak for Integration, which can help you automate application modernization and API management as part of your journey to cloud.
  • An API endpoint is a digital location where an API receives requests about a specific resource on its server.

Web APIs typically use HTTP for request messages and provide a definition of the structure of response messages. These response messages usually take the form of an XML or JSON file. Both XML and JSON are preferred formats because they present data in a way that’s easy for other What is API apps to manipulate. The book distributor could give its customers a cloud app that lets bookstore clerks check book availability with the distributor. This app could be expensive to develop, limited by platform, and require long development times and ongoing maintenance.

api meaning

Leave a Reply