What Are APIs and How Do They Work?

In this application, you are able to see the available holiday destinations, for instance in Europe, the flights available and the hotels you can book your stay in. You go ahead and choose a holiday destination in a European city, book a flight and your accommodation and even make payment. All this happens swiftly without any problems.

This is made possible by Applications Programming Interfaces (APIs). While using the travel application, you interact with many other applications. The travel application communicates with these other applications to provide you with all the details that you need. For instance, it communicated and pulled information from hotel and flight databases to show you the accommodation and flights available. You also made payments, for instance from your bank, meaning that the travel application also interacted with the bank.

All these interactions between the different applications are hidden from the user. You do not see them and everything looks like it is happening within the travel application. This is because of APIs. They hide the integrations from the front-end user. So what are these APIs?

What is an API?

An API is a computing interface that allows applications to communicate and share information with each other. They dictate the calls that are made, how they are made, the conventions used when making the calls, and the data formats used. Its definition here shows what an API is for beginners and can be broken further into three categories;

• The application: This refers to the point of access to the service you are using. It could be a mobile application or a website among others.
• Programming: This is the code written to make it possible for the service you are accessing to initiate communication and transactions between other applications and yourself.
• The interface: This is the frontend view that you are able to see when accessing the service. You interact with this view and feed it with information for the entire system to communicate and provide you with what you need.

Types of APIs

There are three types of APIs that developers work with. They include;

Public APIs

Public APIs are developed by organizations and make them available to third-party developers. These developers can implement them into their applications to tap into the organizations' data or even applications. Some of them are provided for free while others on a premium basis.

Private APIs

Private APIs are developed for private use within a business. The main purpose of these APIs is to make sure that the business applications and their systems are integrated for easy running of the business operations.

Partner APIs

These are APIs developed by two or more businesses that exchange data and information for the success of their operations. For instance, a bank and real estate company can build an API for the successful collection of rental income.

How APIs Work

APIs allow applications to exchange data with each other. The applications use an interface for their communication. Now, let us assume that we have two applications, X and Y. Application X needs a certain functionality that is provided by application Y. For it to get this functionality, it calls an API provided by application Y. It also gives instructions with regards to the functionality it needs. Application Y then receives the request through its API and decides whether to authorize it or not. If it is authorized, then application X will receive the functionality it needs.

For APIs to work, they depend on API documentation that dictates how an API should be implemented. The documentation also makes the entire process easy and fast for developers. It is, therefore, important for API builders to make sure that they have documented their APIs for easier implementation.

Conclusion

APIs have revolutionized software development and made it easy and fast. Today, when building applications, developers do not have to write the entire code from scratch. They can look for APIs with the functionalities that they need then implement them. This, together with the streamlining of business operations, are the main reasons why businesses have adopted the use of APIs. For instance, if you look at the top banking trends in the banking industry, you will find that most of them are fueled by APIs and API-driven innovations. This shows how important APIs are in every industry today.