Product management glosary

API (Application Program Interface)

What is API (Application Program Interface)?

API, or Application Program Interface, is a set of protocols, routines, and tools that allow different software applications to communicate with each other. It defines how software components should interact and exchange data with each other. APIs are widely used in software development to create new applications, integrate different systems, and automate business processes.

How does API work?

APIs work by exposing a set of functions or methods that can be called by other software applications. These functions are usually defined in a programming language, such as Java, Python, or Ruby. When a software application wants to use an API, it sends a request to the API server, specifying the function it wants to call and the data it needs. The API server then processes the request, executes the function, and returns the result to the calling application.

Why are APIs important?

APIs are important because they enable software developers to create new applications and services by leveraging existing functionality. Instead of building everything from scratch, developers can use APIs to access pre-built components and integrate them into their own applications. This saves time and resources and allows developers to focus on creating unique value for their users.

APIs are also important for businesses because they enable different systems to communicate with each other. This allows businesses to automate processes, share data, and create new services that would not be possible without APIs. For example, an e-commerce company might use an API to integrate its website with a payment gateway, allowing customers to make purchases securely and easily.

Types of APIs

There are several types of APIs, including:

  • Web APIs: These are APIs that are accessed over the internet using HTTP requests. They are often used to provide access to web services, such as social media platforms, weather data, or financial information.
  • Internal APIs: These are APIs that are used within an organization to enable different systems to communicate with each other. They are often used to automate business processes, share data, or integrate different applications.
  • Partner APIs: These are APIs that are provided by one company to another company to enable integration between their systems. They are often used to create new services or to share data between different organizations.


APIs are a critical component of modern software development and business operations. They enable different applications and systems to communicate with each other, automate processes, and create new services. Understanding how APIs work and how to use them effectively is essential for software developers, business analysts, and IT professionals.