API – What is an API?


API is an English acronym for application programming interface. In a longer definition,  it is a set of definitions and protocols  that allows software applications to communicate with each other over the Internet. Interface in general is a term in programming that defines the publicly exposed function that can be called by other software.




What the API allows us to do


Today’s APIs are an intermediate layer to retrieve data from different sources. They have been successfully monetized, so a large number of data companies offer the exchange of data that the API can retrieve. For example, if you need information about places or any geographic information, you can use the Maps API, or if you need to process payment, instead of doing it yourself, you can integrate with any payment processing provider and simply pass your data application to a payment API.

API Types


We can distinguish between four types of API

    • Open API:  Public API that is free to use for everyone, without restrictions.

  • Partner API:  APIs not publicly available. They may be used if you have the right and license to use them.

  • Internal API:  This API is not public and is designed especially for internal use of a company.

  • Composite API:  combination of different data and service APIs of the page in the ALT attribute, but they must serve to explain the context or content of the image and avoid over-optimization or keyword stuffing 

How an API works


Now that we know more about the nature of APIs and what we can do with them, let’s see how it works and how they can be called from an application. First of all, we can separate APIs into a few groups based on how they are used:

  • Web API:  Used as a call by sending a specific file structure (json or xml) to a single endpoint which then, based on the input, calculates and returns the data and result.

  • Web Service API:  Represents stored data with different URL mappings and already written logic, so if you want to get, for example, the list of products from some data source, you just have to call it and retrieve the data.

  • Webhook:  it is a URL generated from your side and connected to the service where you expect the data. That Webhook URL is then pasted into the data provider’s services and instead of calling the URL to retrieve data, every time the change occurs on the data provider’s side, the URL is triggered and sent to you the data. This is also known as a return URL.

Depending on your needs you can use any of these types of API. Webhooks are widely used in tracking conversion rates because they can be triggered every time a customer converts. Web services APIs, meanwhile, can be used to populate data on your page if you’re running e-commerce sites , and include all kinds of third-party services that allow you to run complex systems without the need for a technician.