API - Application Programming Interface is a software that allows two different applications which might be written in two languages to communicate and retrieve data from each other without a language barrier. It is as simple as that.
It is software that serves as an intermediary or interface that allows another application to use some of its data which is allowed by the Host application creating the API.
It is a medium that allows two applications to talk to each other.
Let's look at an example to see how an API works and what it does for better understanding.
The common analogy used to describe API is the Food Restaurant analog. But let's take it a step further and make things simpler.
Consider that there is a Bank. In this bank, you get to keep your money and other valuable items.
In other to get money or have access to your values each time you need it, there is a procedure you need to follow, else you won't be given the access. right?
Now there are just two parties involved, you and the bank. But it is usually not an easy option for you to go to the bank directly to retrieve your valuables or withdraw your money. Trust me, it is tedious.
So, in other to ease its customer's pain, the bank decided to provide you with an ATM or a POS which allows you to withdraw your money through your card from the comfort of your home.
This is a lot easier, right? yeah, it is.
There are now three things involved in the process:
The Bank(application): In which you store your money (Information/Data)
The ATM(API): This is what gives you access to your money or valuables
The Customer(application): This is the owner of the money or valuables(Information/Data)
So, this is how the process goes, you have the customer, whenever you need to get or withdraw money, you do not need to go to the bank to have access to this service that your bank offers you.
All you have to do is to use your card to withdraw through the ATM or POS to get your money.
The Bank which is the application that information is needed from creates and gives you an ATM which is the API with which you can withdraw and get your money or information or data from.
API gives you access to information that cannot be accessed directly from an application.
With APIs applications of different types can interact with each other easily. It means users of your application do not have to leave your application to use features of other applications.
A good example of this is the use of the Facebook or Google API to log in or sign up on other applications without having to move out of the application to log in to the app or website.
Google and Facebook API gives the application access to this login information or details through its APIs.
APIs reduce the complexity of having to deal with complex steps involved for two apps written in different languages to send and receive information from each other.
APIs are hugely important in today's economy. These are some of the practices companies use to stay relevant as users or developers use their products directly or indirectly.