API (Application Programming Interface)

An application programming interface (API) connects computers or computer programs. 

The primary role of an API is to simplify communication between devices and programs. It can be defined as a specification of possible interactions with a software component on each side of the connection. 

Imagine using a device without deeply understanding how it works and what happens inside. A simple example would be pushing the acceleration pedal in your car. You don’t need to understand how it works or what allows you to accelerate and move. The acceleration pedal, in this case, is your API point, and in real life, you are surrounded by these APIs almost everywhere.

APIs hide coding complexity from developers, extending systems to partners, organising code, and reusable components. The most popular use of APIs on the internet that you probably use daily are:

• e-commerce payment APIs
• sign-up newsletter forms
• internet website form and CRM connections
• printing using WiFi or NFC communication

A few companies build their business models by using APIs and automation technology. This allows users to connect to a system easily step-by-step without having any knowledge of coding interfaces. Popular examples are Zapier, IFTTT, Microsoft Flow, Automate.io and many more.

You can test API performance and meet criteria using API testing tools. 

Over the last few years, there has been increased interest in API/Web services testing. API testing tools are a software testing type that focuses on determining if a developed API meets expectations regarding functionality, reliability, performance, and security of the application. According to research by MarketsandMarkets, the global forecast for the API testing market predicts that its market revenue will reach $305m by 2022. SmartBear, Parasoft, Micro Focus/HPE, and IBM are market leaders in the API testing tools market.