APIs are fundamental concepts of modern software development. As a programmer, it’s crucial to understand how APIs work, so you can use them to build high-quality desktop, web, and mobile applications.
What Are API References?
An API (Application Programming Interface) is a software layer or intermediary that allows two applications to communicate. For example, when you use Instagram and view a profile, it’s done through an API. For each of these instances, your mobile device sends data to a server over the Web. The server treats this data as a request, processes it, and provides the relevant information, sending it back to your phone.
Types of APIs
APIs are divided into the following types.
- Web APIs
Web APIs are accessible via the HTTP protocol. It specifies request and response format and endpoints. These APIs establish communication with the browser. They can consist of services, such as web storage and web notifications. Various web APIs comprise different levels of privacy and security, including partner, internal, and open APIs. You can also combine two or more web APIs into a composite API.
- Open APIs
Also known as public or external APIs, open APIs are accessible for developers and others with reduced limitations. They can be entirely open, require an API key, or need registration. These APIs are built for external users .i.e. programmers who work for other companies, so they can access services or data. For instance, consider Google Maps API – any developer can use it to integrate Google maps in a website or mobile app.
- Internal APIs
Internal APIs are built to be kept hidden from external developers or users. Their purpose is to improve the sharing of resources in an organization. Any department or team from the organization can use these APIs to access each other’s programs, data, and tools. Internal APIs are preferred over traditional integration options because they offer a wide range of advantages, such as access control, security, and an audit trail of system access.
- Partner APIs
Technically, partner APIs bear a resemblance to open APIs. However, they come with restricted access, which is mostly controlled via a third-party API gateway. They are designed to meet a fixed goal – for instance, offering access to a paid online service.
- Composite APIs
Composite APIs enable developers to use a single call to access multiple endpoints. In this way, you can call multiple data sources and services. These APIs are commonly used in microservices architecture, where a user may require information from multiple services to achieve a single task. Taking advantage of composite APIs enhances application performance and decreases server load, where one call can return all the data according to user requirements.
Web Service APIs
A web service is a software or a system that makes use of an address .i.e. you can access them through an URL on the Internet. Some of the most common web service APIs includes the following.
An RPC (Remote Procedure Call) APIs helps the client to execute code on a server. They are useful because they make it convenient for coders to build applications that involve multiple services and programs. There are further divided into two categories.
These APIs are built by formatting your data in XML. You can use them to make basic requests to the server through the HTTP. However, do keep in mind that these APIs are tightly coupled. Before making any modifications, a new coder must read its documentation and learn how a modification in one area could influence others.
A SOAP (Simple Object Access Protocol) API is a form of Web API. It is being used since the late 1990s where it was primarily used for service-oriented architectures. SOAP was different because it standardized the manner in which software could utilize network connections for managing services. Since W3C has defined SOAP as an official protocol, it follows strict rules, particularly for security. For instance, you have to integrate compliance measures like ACID into the SOAP APIs.
REST (Representational State Transfer) is a web services API. REST APIs are used in all modern applications, such as Amazon, Uber, and Netflix. A RESTful API sticks to the following:
- Stateless – A REST API is stateless in nature.
- Uniform Interface – A client and server interact with each other using URIs (Unique Resource Identifiers), JSON conventions, and CRUD (Create, Read, Update, Delete) via HTTP.
- Client Server – The server and client aren’t dependent on each other. Any revisions made in the server don’t impact the client.
- Cache – The client needs to have the capability of caching the responses. This is beneficial for enhancing the user experience by making them more efficient and faster.
- Layered – The API needs to complement a layered architecture where each layer contributes to a clear hierarchy. Layers must be loosely coupled, allowing encapsulation.
Want to try using an API? You can start by working with Image-Charts API. With this API, you can easily create different charts and improve your data visualizations.