Introduction to API
Tags: api, beginners
Published: 2023-06-27 14:36:16

**INTRODUCTION TO API**

An **Application Programming Interface (API)**  is a means for two or more software programs or applications to communicate and share data with each other using a set of  protocols. The word Application refers to any software with a definite function while Interface can be a sort of contract  of services between two applications. This contract describes how the two applications communicate using requests and responses. API documentations contains information on how developers will structure the requests and responses.

![API](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ij547nsysuc2ymbsc0t5.png)
                     
 APIs are often made up of different components that acts as tools available to the programmer. A program or applications that uses one of the components is said to call that portion of the API, such calls that make up the API are known as subroutines, methods, requests or endpoints. API specifications explains how to implement this calls.

![How API works](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ejeiyxbksep368phdjek.png)
                                  

**API DOCUMENTATION,SPECIFICATION AND DEFINITION**

**API documentations** are reference manuals that helps developers and other API consumer understand and utilize the API effectively. They should be well-designed, comprehensive and easy to follow.  A great API documentation usually includes;

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Quick start guide

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Tutorials 

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Interactive documentation.

**API specification** gives a broader understanding of how an API behaves and how the API links with other APIs, it also explains the API functions and expected results when using the API. There are several API specification formats, each with its own syntax and tooling ecosystem. When creating an API, choosing an API specification format and following its guidelines can aid API development, collaboration and adoption.

**API definition** also like API specifications provides understanding on how an API is organized and how it functions but API definition is directed at machine consumption instead of human consumption 

**TYPES OF APIS**

There are four different type of APIs commonly used, They include;

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**Public APIs:** open and available for any developer to use, also called open APIs or external APIs.

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**Partner APIs:** available to selected and authorized developers or API consumers.

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**Private APIs:** available for use within an enterprise to connect systems within the business, also called internal APIs.

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**Composite APIs:** is the combination of two or more APIs to create a sequence of related operations.

**PURPOSE OF APIS**

APIs are very essential components of the modern software and technology development. They serve several purposes including:

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**Data Access and Sharing:**  APIs provide a structured way to access and share data between different applications and software thus making it possible for developers or API consumers to utilize the functionalities and information of other applications.

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**Integration and Interoperability:** APIs provide a standardized way for different software and applications to communicate and interact with each other enabling developers to enhance functionalities from other software without building from scratch thus simplifying the development process.

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**Encapsulation and Security:** APIs provide a secure way to expose only necessary functionalities for external use while keeping sensitive information and implementation hidden by encapsulating the internal workings of a system.

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**Collaboration and Ecosystem Development:** APIs facilitates ecosystem development of applications,tools and software that work together and also collaboration between different developers thus promoting innovation and expanding capabilities of software systems.


**CONCLUSION**

Overall,APIs have revolutionized the way applications are built, integrated, and scaled. They empower developers to leverage existing services, extend functionality, and build innovative solutions by promoting collaboration and ability of a software to work with another software. With the continued growth of technology and increasing demand for interconnected systems, APIs will undoubtedly remain a critical component for modern software development for years to come.