API stands for “application programming interface.” An API enables two or more computer programs to speak with one another. APIs connect applications, enabling them to provide services and transfer information.

In today’s day and age, they are an essential piece of the early development lifecycle for businesses across the world. However, it’s important to know the best type of API you need for your particular application.

Different types of APIs

As technology continues to progress, APIs have also evolved to serve different purposes. This is why there are different types of APIs. Read on to learn about some of the most popular API types and their main functionalities.


REST stands for “REpresentational State Transfer.” This is the most common type of API that is used today and is easily implemented across the internet because of its HTTP functions, including GET, POST, PUT, DELETE, OPTIONS, and PATCH. Formatted in JSON and XML, REST APIs make data easily available on the server.

REST APIs are usually used to interact with objects in a system and are helpful when building basic, resource-driven apps. They are cache-friendly, they support multiple formats, and they’re flexible, which allows for continual system growth. Unfortunately, the “RICH” metadata can sometimes slow down the process.

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SOAP stands for “Simple Object Access Protocol.”

One of the benefits of using a SOAP API is its ability to safely work with legal contracts, codify terms, and safely pass sensitive data back and forth. It also has native error handling built in. This can stop problems in their tracks before they grow into larger issues.

SOAP is a popular API type with developers and is formatted as XML files. However, its popularity has been declining because SOAP’s standardization format can be extensive and the XML files are large. That can be a strain on simpler systems. Their declining popularity has also created less demand for people who specialize in SOAP servers, which can make it especially difficult to maintain.

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Open APIs are also called public APIs. They are an API made open and available to software developers. They allow software tools to talk with and pass data between each other.

With an open API, developers can use technology that’s already been created, fostering innovation and continual evolution of applications. Instead of having to start from scratch with the functionality an existing app offers, apps can be used and continually improved upon.

Because open APIs can interact with other systems, it can make an app more marketable to consumers. For example, Facebook provides an open API that allows cross-interaction with other third-party tools and applications. Its ability to cross-post to other apps is a function of having an open API.


gRPC stands for “Remote Procedure Call” and was developed by Google. It’s an open-source, universal framework for microservice communication.

You can efficiently choose server functions remotely. The server then speaks to the other applications, decodes the message, and performs the request. This is ideal for real-time applications as the user can see the outcome of their request to the server.

Overall, using gRPC is simple and straightforward. The performance of gRPC is excellent and the functions are easy to add. You can define any type of function, making it almost endlessly configurable. However, one of the primary concerns with gRPC is that it doesn’t have robust security because of its lack of an abstraction layer between the system functions and the API.

Which API works for you?

While there is no “one size fits all” for APIs, there is an API type that can work well for your unique needs. Before you decide which type to choose, consider the programming language you would like to use, the environment in which you’re going to be developing, and your resources. It’s also important to know who will be responsible for maintaining and working with the API and the extent of their current work capacity and knowledge of the procedures involved.

Are you wondering how eOne Solutions can make this an easier decision for you? Contact our sales team at sales@eonesolutions.com or 888-319-3663 ext. 1 for more personalized help answering your questions.