APIs are the little pieces of code that make it possible for digital devices, software applications, and data servers to talk with each other, and they’re the essential backbone of so many services we now rely on. An API is a set of definitions and protocols for building and integrating application software. API stands for an application programming interface.
APIs are not restricted to web applications or even to software applications. Anything that can be controlled by software by definition has an API. The API for some hardware pieces may require reading/writing specific values to specific addresses in memory or using a specific sequence of inputs/outputs in an I/O port.
APIs let your product or service communicate with other products and services without having to know how they’re implemented. This can simplify app development, saving time and money. They work as the middleman, allowing developers to build new programmatic interactions between people and various applications daily.
For every API that you use in your app, you first need to generate an API key to use it inside your app. The key is generated so that the service providers can track your requests. Many travel websites use APIs of different airlines, hotels, etc., to provide the users with information regarding seat availability, room availability, locations, timing, and many more. Even Google maps provide APIs which you can use for any purpose inside your app. The process remains the same. To generate a key at first and then use the API accordingly by studying its documentation.
There are hundreds of APIs for finance, travel, social messaging, payments, e-commerce, and multiple other categories covering everything we do with applications. The fastest-growing category of APIs over the past years is for the sharing and analyzing of data across various applications — an area where the API characteristics determine the value of the application or deem it untenable for use in the real world.