A Comprehensive RESTful API Tutorial

Posted on September 30, 2021 How-To Guides

Technology is evolving at a pace we can barely keep up with. The internet, computers, and smartphones are now capable of things we could only dream of five to ten years ago.

New advancements in IT like cloud computing and the use of APIs are partly responsible for this exponential growth. Today, we’re going to talk about the RESTful API. 

RESTfuls, and other APIs, are helping computers to increase their power by leveraging the performance of other apps. We’re going to dive into exactly how this is possible and what it can help you and your team accomplish.

By the end of this article, you’ll be your team’s “go-to” person for API technology. Who knows? You may even find a groundbreaking way for your team to use a RESTful API and get yourself a raise!

What Is An API Exactly?

Some of you may be familiar with the term API. If you’re not, that’s ok. This is a fairly new technology that’s been helping to expand the capabilities of computers around the globe.

API stands for application program interface. In its simplest form, an API is a set of programming rules that dictate how one computer program interacts with another.

How does this apply to the real world? Well, the best way to describe it is to think of your computer as an outlet. An outlet with thousands of receptacles to plug things into.

APIs are the technology by which you can “plug” other programs into your computer so that they can work together. APIs have the ability to do this because they can help to return data input in a format that your computer can use.

Some of these formats include XML and JSON. When it comes to RESTful APIs, however, we only need to focus on JSON.

What Separates A RESTful API?

So, what makes a RESTful API different than the rest? It has to do with the architecture of the API. REST stands for representational state transfer. All it means is that RESTful APIs are good at returning data to an application in the format that’s most useful for that application.

It plays to the strengths of the application it’s working with.

It’s important to note that REST is not a standard protocol within APIs. This is a more modern framework developers are using to design APIs to help them work together more efficiently.

For this to work, your data servers need to have REST API capabilities. If they do, you can then make requests on these servers from the client’s end. At that point, the API is RESTful.

REST Principles

Another reason why the RESTful API is different than its traditional counterpart is the principles that govern its architecture. The original designer of the framework was able to identify six key principles that make an API RESTful.

1. RESTful APIs Are Stateless

Requests sent from a client program to a data server contain all of the information needed to process the requests. Requests can function as part of a query string, URL, or other parameters.

Once a user sends a request, the body remains in the state of the requesting resource.

What does this mean for you? Well, how much easier would it be to process and manage data if it stays in the format of your original client program? There’s no converting or translating necessary.

2. They Have A Uniform Interface

RESTful APIs help to maintain a uniform look across applications. It does this through resource identification, hypermedia, self-descriptive messages, and resource manipulation.

Again, achieving uniformity in this way makes it easier for you to use your data throughout the application. Data can be created, updated, deleted, and read with ease.

3. Make Code Changes On Demand

RESTful APIs are also more flexible than traditional APIs. What makes them this way is the fact that additional sections of code, or applets, can be downloaded and plugged into the original framework of the RESTful API. It allows RESTful APIs to have the same functionality as open-source software.

4. Layered System

RESTful APIs contain layers. The idea behind this structure is to make the interface more stable. It does this by limiting the behavior of the API’s components.

Because the components exist in layers, one component can only interact with components in the same, or next immediate, layer. Any interaction between components beyond that isn’t possible.

What this does is creates an API framework with better security than traditional API structures. It also helps to evenly distribute the workload put on the API and creates shared web caches. The development of shared web caches makes RESTful APIs very convenient when it comes to scalability.

5. Cacheable

The cacheability of RESTful APIs is one of their most helpful features. Not only does it help with scalability, but it also helps to improve the performance of the API. 

When responses come in from server requests, the API labels these responses as cacheable or non-cacheable. Once a response is labeled as cacheable, it can be used for similar requests in the future.

6. Client-Server Architecture

RESTful APIs are structured in a client-server format. The advantage here is that it keeps clients and servers separate. This allows servers to be used across multiple platforms.

It also helps with the scalability of server performance.

What Can She Do?

So, what can this do for us? RESTful APIs can perform several functions, but they boil down to four main categories.

The API can help clients receive data in a convenient format. It also can help update or delete data from your server’s database. And, finally, it can help your servers to more conveniently create new data.

How does it do this? Well, the RESTful framework relies on the computer programming protocol known as HTTP. You’re probably familiar with this from most web addresses on the internet.

Explaining HTTP protocol is another job for another day. What you need to know about HTTP regarding RESTful APIs, however, is that it helps them complete some complex functions.

The four requests developers can make of a RESTful API within the HTTP framework are GET, POST, DELETE, PUT.

If you make a GET request of your RESTful API, you’ll be able to get information and bring it into your system in a convenient format. The POST protocol is handy when you need to create new data.

DELETE, as the name implies, allows the API to help you with deleting data. And PUT is the HTTP protocol used for data updates.

Within HTTP protocol, all of these request formats fall under the CRUD framework. This stands for Create, Read, Update, and Delete, data.


The world of APIs is constantly changing. As a result, there are going to be changed in APIs. We can’t avoid that.

What we can do, however, is prepare for them. The way developers do this is by a process called versioning.

Web developers use versioning to avoid future issues with compatibility after a RESTful API has been created. The one drawback to this technique is that it may increase a server’s workload. The reason is that the server has to host multiple versions of the API on the same network.

When a new version of a RESTful API is created, older versions remain on the website’s data servers. Eventually, these older versions can be removed to help make room for more updated RESTful API endpoints.


Once a RESTful API begins operating, it’s an open system. This means that anybody can send requests to the server. The result would be a lot of requests and data flying back and forth. 

The problem with this is that data requests are often used as an entry point for hackers. With so many requests and data transmissions happening at the same time, it’s easy for them to slip in undetected. Then you have a big problem on your hands.

Applications on the client’s side of a particular server can use cookies to their advantage. These cookies can validate a request on the API and make sure the user making the request has the appropriate user rights and credentials.

Occasionally, a company may use a third-party platform to help with its user authentication. A real-world example of this is when users attempt to get directions through a GPS, or map, API. These third-party authentication platforms can also be helpful for security.

Using a third-party platform does this by helping to protect users’ documents or emails.

Rest Easy With RESTful APIs

The main function of RESTful APIs is to make your daily tasks easier. Use them to connect and protect your data and keep your team running smoothly.

If you haven’t yet, we strongly suggest implementing the power of APIs to take your business to the next level. For questions about RESTful APIs, or any other internet and cybersecurity concerns, contact us at any time.

The team at NETdepot is more than happy to help. Our team of experts can help you to come up with a network solution that’s right for you.

Contact Us Today To Experience How We Can Save You Time, Money And Stress