API – A Standard for Integrating Multiple Applications

The API is an acronym for Application Programming Interface, which is being used for online transactions.

An API is an IT solution that allows applications to communicate and share services or data with each other. This type of application programming interface literally represents the evolution of the web. Since the appearance of the Internet, websites have grown to allow individuals to trade and businesses to sell their products to customers online.

In that sense, an API is a standardized set of functions, classes, methods, and constants that serves as a facade through which software offers services to other software. It is offered by a software library or web service, usually accompanied by a description that specifies how consumer programs can take advantage of the vendor’s program functionality.

Therefore, it is a standard for collaboration between IT programs or services in such a way as to enable reuse.


The API provides the ability to present a catalog of functionalities that come from the application, or even content that comes from a database or file system, both on the internet and on the local network of the company.

With the increasingly intensive process of digitalization of innumerable business ranges, the API has become a standard technology for the integration of several business applications. Web and software players also use it more to provide programmatic access to offers, rather than just in the form of traditional graphical interfaces.

When you use the application on your mobile phone, the application connects to the Internet and sends the data to the server. The server then downloads this data, interprets it, performs the necessary actions, and sends the data back to your phone. 

The application then interprets this data and presents the requested information in a readable mode. The API allows the entire process to take place in a unique way as all data passes through it.

Application programming interfaces generally offer a set of functions that enable queries and access to application services through a programming language.


The purpose for which they were created is to enable third-party systems to access these functions and content. In other words, the purpose of APIs is therefore to allow several software programs to interact.

In the way that the telephone directory dialing service made it possible to obtain the number of another contact, the API acts as a directory, allowing a computer to request information from another computer over the internet.

In order to improve the provision of services in this area, it is necessary to integrate and connect the offer with various software programs that enable mutual communication. This is exactly the area in which the API can show efficiency, providing maximum flexibility, simplicity, and controllability, all in a more simple way compared to any other method.

The API provides the ability to remotely access application functions or data, usually from another application, via a standard interface. This request is sent to the target software in a universal language. The API language, which is a type of universal Esperanto, allows the requested software to understand what is required, and then to perform actions and deliver the required content.


When it comes to API categories, it can be divided into three broad groups, which include open API that is publicly available without restrictions, internal or private API, which companies design according to their own needs, as well as partner API, which is available through license or special access right.

An open API, sometimes called a public API, is an application programming interface that allows a developer to programmatically access a proprietary software application.

On the developers’ side, the API defines how to write a program that requires services from the operating system or other application. APIs are implemented by so-called function calls that consist of verbs and nouns, while the syntax required is described in the documentation of the application that is being called.

Typically, APIs are published for third-party development as part of the SDK software development kit or as an open API published on the internet.

If the applications are written in different languages or for different platforms, the communication between the two applications is enabled by the middleware that is providing messaging services.

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This content was brought to you by VISA, the global leader in digital payments, whose mission is to connect the world with an innovative and secure payment network to enable individuals, businesses, and economies to grow.

Visa is the general partner of the Fintechlopedia project, an electronic glossary containing all relevant elements of digital transactions and related phenomena, situations, processes, and innovations.