API stand for Application Programming Interface (API) is a software interface that allows two applications to interact with each other without any user intervention. API is a collection of software functions and procedures. In simple terms, API means software code that can be accessed or executed. API is defined as code that helps two different software programs communicate with each other and exchange data.

What is an API integration?

API integration can be defined as the process of creating a means for two or more APIs to share data and communicate with each other without human interruption. It involves the use of APIs to enable communication between two web tools or applications. It allows organizations to automate their systems, enhance the seamless sharing of data, and integrate current applications.

API integration has become pivotal in the modern world due to the explosion of cloud-based products and apps. As such, organizations need to create a connected system where data will be relayed flawlessly between various software tools without the need to do it manually. API integration has proved to be the much-needed solution as it allows the sharing of process and enterprise data among applications in a given ecosystem. It improves the flexibility of information and service delivery, as well as makes the embedding of content from different sites and apps easy. An API acts as the interface that permits the integration of two applications.

How do APIs work?

API architecture is usually described in terms of client and server. The application that sends the request is called the client and the application that sends the response is called the server. So in the weather example, the desktop weather database is the server and the mobile app is the client.

To understand the functionality of the API, let see the following example:

API Example:

Let’s see how the API works with a simple everyday example. Imagine that you are going to a restaurant for lunch or dinner. The waitress comes up to you and hands you a menu card, and you adjust your order as if you wanted a veggie sandwich but no onions.

After some time you will receive your order from the waiter. However, it is not as easy as it seems because there is a process going on in between.

Here the waitress plays an important role because you don’t go to the kitchen to take an order or tell the kitchen staff what to do for the waitress.

The API does the same thing, takes your request and like a server, tells the system what you want and returns a response.

There are four different ways that APIs can work depending on when and why they were created.

REST APIs:

It is the most popular and flexible API found on the web today. The client sends the request as data to the server. The server uses this client input to perform internal functions and returns output data to the client. Let’s take a closer look at the REST API below.

SOAP APIs:

These APIs use Simple Object Access Protocol. Client and server exchange messages using XML. This is a less flexible API that was more popular in the past.

RPC APIs:

These APIs are called Remote Procedure Calls. The client completes a function (or procedure) on the server, and the server sends the output back to the client.

Web socket APIs:

Websocket API is another modern web API development that uses JSON objects to pass data. A WebSocket API supports two-way communication between client apps and the server. The server can send callback messages to connected clients, making it more efficient than REST API.

What are REST APIs?

REST stands for Representational State Transfer. REST defines a set of functions like GET, PUT, DELETE, etc. Which allows the client to access data on the server. Client and server exchange data over HTTP.

The main feature of the REST API is statelessness. Stateless means the server doesn’t save client data between requests. A client’s request to a server is similar to the URL you type in your browser to visit a website. The response from the server is simple data without a typical graphical representation of a web page.

What is web API?

A web API or web service API is an application processing interface between a web server and a web browser. All web services are APIs, but not all APIs are web services. REST APIs are a special type of web API that use the standard architectural styles discussed above.

Various terms around API, such as Java API or Service API, exist because historically API was created before the World Wide Web. Modern web APIs are REST APIs and the terms can be used interchangeably.

Two type of web APIs

1. Server-side:

A server-side web API is a programming interface consisting of one or more publicly open endpoints for a defined request-response messaging system. Usually expressed in JSON or XML

1. Client-side:

A client-side web API is a programmatic interface helps to extend functionality within a web browser or other HTTP client.

Why would we need an API?

There are some reason for using APIs:

• API, short for Application Programming Interface, helps two different software programs to communicate with each other and exchange data.
• It helps you embed content from any website or app more efficiently.
• The API accesses application components. The provision of services and information becomes more flexible.
• Generated content can be published automatically.
• Allows users or companies to customize the content and services they use most often.
• Software needs to change over time, and APIs help anticipate changes.

Features of API

There are some important features of APIs:

• It helps you plan a business model.
• Simple, flexible, quickly accepted.
• Controlled and measurable.
• Offers great developer support.
• Offer valuable services (data, functions, audience).

What are the benefits of REST APIs?

REST APIs offer some main benefits:

1. Integration

APIs are used to integrate new applications into existing software systems. This increases development speed because not all functionality has to be rewritten from scratch. You can use the API to use existing code.

2. Innovation

Entire industries can change with the emergence of new applications. Businesses must respond quickly and support rapid deployment of innovative services. They can do this by making API level changes without having to rewrite all the code.

3. Ease of maintenance

The API acts as a gateway between the two systems. Every system has to make internal changes to keep the API from breaking. That way, future code changes on one side don’t affect the other.

Types of API

APIs are classified according to their architecture and scope of use. We’ve explored the main types of API architecture, so let’s take a look at what they cover.

There are mainly four main types of APIs:

1. Private APIs: They are internal to the company and are only used to interconnect systems and data within the company.
2. Public APIs: They are publicly accessible and can be used by anyone. There may be permissions and fees associated with this type of API.
3. Partners APIs: They are only available from official third-party developers to support business partnerships.
4. Composite APIs: This type of API combines different data and service APIs.

What is API Testing Tools

The API testing strategy is similar to other software testing methods. Its primary focus is validating server responses. API tests include:

Postman

Postman is a Google Chrome plugin and can be used to test API services. This is a powerful HTTP client for checking web services. For manual or exploratory testing, Postman is a good choice for API testing.

Download links: https://www.postman.com/

How to use an API?

There are steps to implement a new API include:

• Get API key. This is done by creating a verified account with the API provider.
• Set up the HTTP API client. This tool allows you to easily construct API requests using generated API keys.
• If you don’t have an API client, you can try building your own request in your browser by referring to the API documentation.
• Once you are familiar with the new API syntax, you can use it in your code.

Frequently asked questions

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