Currently, APIs in general and Web APIs in particular are being applied more and more. Modern application architectures are increasingly distributed and language-agnostic, which drives the adoption of APIs.
API (Application Programming Interface) is a crucial bridge that enables software to communicate with each other. In the software development process, both backend developers and frontend developers need to understand APIs clearly in order to build and leverage systems effectively.
Backend developers are responsible for designing APIs to provide data and handle business logic on the server, while frontend developers use those APIs to display information in the user interface.
In this article, we will learn together: what an API is, what a Web API is, and delve into common API types today such as REST, GraphQL, Webhook, etc. We will also analyze their characteristics, how they work, and why they are widely applied in specific domains.
API stands for Application Programming Interface. It is a set of definitions and protocols that allows software applications to communicate and interact with each other. You have probably heard of the term User Interface, which is where a user interacts with our application. Similarly, when software “talks” to each other, they need a special interface called an API.
For example, when you use a weather app on your phone, that app may call the API of a weather service in order to fetch data and display the weather information for you.
A Web API is the system of APIs used in website environments. Almost every website uses Web APIs to let you connect, fetch data, or update a database. For example: when you implement a login feature via Google, Facebook, Twitter, GitHub, etc., that means you are calling that platform’s API. Likewise, mobile apps also fetch data through APIs.
Windows or Linux have many APIs. They provide API documentation that specifies functions, methods, and connection protocols. This helps developers create applications that can interact directly with the operating system.
An API describes and prescribes the desired actions that a library or framework offers. An API may have multiple different implementations, and it also helps a program written in one language use a library written in another language. For example, you can use PHP to invoke a PDF-generation library written in C++.
The first application of APIs that Viettel IDC wants to share is the search function. One could say this is a basic tool for all websites. Without a powerful, common-use search API, users may find it difficult to locate the desired information when their search query is too complex or too specialized.
Therefore, a website needs a strong, widely used API that allows users to search quickly and accurately. This not only enhances the user experience but also creates a positive impression on visitors.
As we know, popular social media platforms like Facebook or Zalo have become huge markets, attracting large numbers of users worldwide. Most modern websites today are integrated with social media channels.
To do this, developers or web designers need to use the social media platform’s API and embed its social functions into their own website.
Through the API, the website and social media platforms can easily exchange data back and forth. Consequently, users do not have to leave the website to interact with the social network normally.
Not only does an API improve user experience, but it is also an essential support tool for developers, especially when building website systems. APIs are widely used to design e-commerce websites on platforms such as Shopify (an online-sales platform with all the functionality of an e-commerce site).
By simply using Shopify’s API attached to website components, users will have the basic features of a standard e-commerce site. This shortens the time required to build a website while still ensuring all necessary features for a typical online store.
Finally, APIs are used to build complex systems such as travel websites or hotel-restaurant websites, and any site that requires a professional booking system so that customers can book services directly on the website. APIs play a tremendously important role in supporting booking features, delivering the best user experience on professional, modern websites.
APIs can be categorized in many ways, but below are some common types:
API (Application Programming Interface) is a set of rules and protocols that allow different applications to communicate with each other. To better understand how an API works, let’s look at these basic steps:
• Request: One application (the client) sends a request to another application’s API (the server). This request usually includes a URL, HTTP method (GET, POST, PUT, DELETE), and may include data or parameters.
• Request Processing: The server receives the request and processes it. This process can involve fetching data from a database, performing computations, or calling other services.
• Response: After processing, the server sends a response back to the client. This response is usually in JSON or XML format and contains data or information about the result of the request.
• Displaying the Result: The client receives the response and displays the result to the user or continues processing the data according to the application’s logic.
Example: When you use a weather app to view a forecast, that app sends a request to the weather service’s API, receives a response containing forecast information, and displays that information on your screen.
REST API (Representational State Transfer) is a popular API architecture designed to take advantage of standard HTTP methods. Below are some key points about REST APIs:
• HTTP Methods:
– GET: Retrieve data from the server.
– POST: Send new data to the server.
– PUT: Update existing data on the server.
– DELETE: Delete data from the server.
• Resources:
In REST, everything is considered a resource, and each resource is identified by a unique URL. For example, a user resource might have a URL like https://api.example.com/users/1.
• Stateless:
A REST API does not store the client’s state between requests. Each client request to the server must include all information needed to understand and process that request.
• Data Format:
REST APIs commonly use JSON or XML to exchange data between client and server. JSON is more prevalent today due to its readability and lightweight nature.
• HATEOAS (Hypermedia As The Engine Of Application State):
One principle of REST is that the server can provide hyperlinks in its response to guide the client on subsequent possible actions.
REST APIs are highly flexible and easy to use, which is why they are favored for developing web and mobile applications.
Benefits of REST APIs
REST APIs bring several important benefits, making them a popular choice for application development. Below are some key advantages:
• Ease of Use and Understandability:
REST APIs use standard HTTP methods, which are easy to understand and use. Developers can quickly grasp and implement them.
• Flexibility:
REST APIs can handle various data formats and can be used with any programming language that supports HTTP.
• High Performance:
Since REST APIs use lightweight HTTP methods and are stateless, they can handle requests quickly and efficiently.
• Scalability:
REST APIs can be easily scaled to meet the demands of large and complex applications. Resources can be added or updated without affecting other parts of the API.
• Compatibility:
REST APIs can work across multiple platforms and devices, from desktops to mobile phones, enhancing compatibility and integration.
• Security:
REST APIs can employ standard security mechanisms such as HTTPS and OAuth to protect data and authenticate users.
• Excellent Support for Web and Mobile Applications:
REST APIs are well suited for web and mobile apps, where fast and efficient data exchange is required.
If you don’t know what a Web API is these days, you’re at a disadvantage. A Web API is a type of API that is very commonly used in most websites.
Simply put, a Web API is the method that allows separate web applications to communicate and exchange data with each other. Thanks to this, users can connect and update databases easily and quickly.
The most common example is when you use your Google account to log in to a social network like Facebook. In this case, both Google and Facebook must understand the Web API protocol to exchange data with each other.
Web API supports full RESTful methods such as GET, POST, PUT, DELETE. It also fully supports HTTP components, making it simple and fast to build HTTP services.
Advantages:
Disadvantages:
API integration is the process of connecting and using APIs to allow different applications or systems to communicate and exchange data with each other. Below are some key points about API integration:
API integration allows different systems to connect and work together seamlessly. For example, an e-commerce application can integrate a payment service API to process online transactions.
By using APIs, processes can be automated, minimizing human intervention and increasing efficiency. For example, an inventory management system can automatically update stock levels when a new order is placed.
API integration enables applications to extend their functionality by using external services. For example, a mobile app can integrate a mapping API to provide location features to users.
APIs help applications exchange data quickly and securely. For example, a CRM application can integrate an email service API to send automated emails to customers.
By integrating services and features from various APIs, applications can offer a richer and more engaging user experience.
To create an API, you can follow these basic steps:
Identify the goals and functionality of the API. Decide which endpoints and HTTP methods (GET, POST, PUT, DELETE) the API will support.
Choose a programming language and framework. For example, you can use Node.js with Express, Python with Flask or Django, or Java with Spring Boot.
Use tools like Postman or Insomnia to test the API endpoints and ensure they work correctly.
Write detailed documentation on how to use the API, including endpoints, parameters, and examples of requests and responses.
Deploy the API to a server or cloud service such as AWS, Azure, or Heroku so that users can access it.
API testing is the process of verifying that an API’s endpoints function as expected. Below are some key aspects of API testing:
Ensure that API endpoints operate correctly according to defined functional requirements. For example, check whether a valid request returns the correct data.
Evaluate response speed and load-handling capacity of the API. This includes checking whether the API can handle a large volume of requests within a short timeframe.
Ensure that the API is protected from security vulnerabilities. This involves testing authentication, authorization, and data encryption.
Ensure that the API works well across different environments and devices.
Identify and handle errors that may occur when the API receives invalid requests or encounters issues.
APIs play a pivotal role in connecting software systems, enabling effective communication between frontend and backend, and offering flexible integration between platforms and services. Understanding various API types such as REST, GraphQL, or Webhook not only helps developers choose the right solution for each specific scenario but also improves development efficiency and system scalability. In today’s digital era, mastering API knowledge is a significant advantage for anyone working in software development.
