What is APIs?
API is basically a set of functions and procedures which allow one application to access the feature of other application REST is a set of rules or guidelines to build a web API. It is basically an architectural style for networked applications on the web which is limited to client-server based applications. APIs also allow developers to add features and functionality to software by utilizing a rich array of other developers’ APIs. Much of today’s enterprise, mobile and web software depends on a wide range of APIs.
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How many Types of APIs?
APIs are extensively accepted and used in web applications. There are four different types of APIs commonly used in web services: public, partner, private and composite. In this context, the API “type” indicates the intended scope of use.
Public APIs. A public API is open and available for use by any outside developer or business. An enterprise that cultivates a business strategy that involves sharing its applications and data with other businesses will develop and offer a public API.
![](https://www.devopsfreelancer.com/blog/wp-content/uploads/2023/07/image-56-1024x576.png)
Partner APIs. A partner API, only available to specifically selected and authorized outside developers or API consumers, is a means to facilitate business-to-business activities. For example, if a business wants to selectively share its customer data with outside CRM firms, a partner API can connect the internal customer data system with those external parties — no other API use is permitted.
![](https://www.devopsfreelancer.com/blog/wp-content/uploads/2023/07/image-57.png)
Internal APIs. An internal or private API is intended only for use within the enterprise to connect systems and data within the business.
![](https://www.devopsfreelancer.com/blog/wp-content/uploads/2023/07/image-58-1024x410.png)
Composite APIs. Composite APIs generally combine two or more APIs to craft a sequence of related or interdependent operations. Composite APIs can be beneficial to address complex or tightly related API behaviors and can sometimes improve speed and performance over individual APIs.