REST API vs RESTful API Explained Simply – Complete Guide for Modern Developers

If you're developing mobile or web applications, there’s a high probability that you’re working with APIs, more specifically REST APIs. Within that context, APIs allow developers to build today's mobile and web applications, which can implement significant features (e.g., user authentication, product information, payment processing, etc.) as well as provide a mechanism for application notifications. In this tutorial, we'll explore the key differences between REST and RESTful Types of APIs. We will provide examples as well as industry standards/best practices to illustrate what makes a REST API functionally important for building scalable applications.

Understanding the REST API (with an example)

A REST API (Representational State Transfer Application Programming Interface) is an interface (API) that enables communication between two separate applications via the internet, through the use of standard HTTP methods. At its core, a REST API allows one application to make a request for certain pieces of information while another application provides said information (in most cases, as JSON). The REST API format has become popular because of its lightweight design and fast response time (as compared to a traditional API), as well as the relative ease of implementation across multiple platform types.

Most Common REST API Methods (HTTP)

REST APIs utilize standard HTTP methods to perform four (4) basic functions related to data storage and retrieval:

• GET – used to retrieve existing data
• POST – used to create new records
• PUT/PATCH – used to update records
• DELETE – used to delete records

RESTful API

The definition of a RESTful API is an API that abides by the guidelines and architecture of REST. All REST APIs can be called RESTful APIs, but not all REST APIs qualify as RESTful. The RESTful API:

• Uses the proper HTTP methods.
• Has easy-to-read, resource-based URLs.
• Is stateless, meaning that the requests are independent of one another.
• Returns HTTP status codes defined by standards.
• Uses JSON to exchange data.

For example, the URI GET /api/users/101 shows that the URI references a "user" resource that has an ID of "101".

REST API vs RESTful API - Differences

• Definition: REST APIs follow some of the REST ideas; however, they may not comply with all of the REST principles. RESTful APIs follow REST architecture completely.

• URL Structure: REST APIs may have inconsistent or non-resource-based URL structures, whereas RESTful APIs consistently have readable, resource-based URLs.

• HTTP Methods: REST APIs may misuse HTTP methods, while RESTful APIs correctly use the GET, POST, and PUT/PATCH/DELETE methods.

• Statelessness: REST APIs may or may not be stateless. RESTful APIs are always stateless because each request is independent.

• Scalability: RESTful APIs are designed to be highly scalable, while REST APIs are often limited in their scalability.

• Maintainability: It is easier to maintain and extend RESTful APIs than to maintain REST APIs, which usually end up being inconsistent.

• Predictability: RESTful APIs are predictable and structured; REST APIs may not have clear structures; therefore, it may be challenging to use them consistently.

Why RESTful APIs are the Best Choice in Modern Development:

RESTful APIs are the best choice for developing API's because they: 1. Are Fast and Lightweight 2. Are Simple to Maintain and Grow 3. Are Platform and Language Independent 4. Can be Used with Web, Mobile, and Cloud Applications

Many companies are using RESTful APIs for:

1. eCommerce Sites 2. Payment Gateways 3. Social Media Apps 4. ERP and CRM Software Systems 5. Microservices Architecture

Let’s Look at a Real Example of a RESTful API In Use:

A sample RESTful web application would look like this: 1. Retrieve all products: GET /api/products 2. Retrieve a single product: GET /api/products/501 3. Create a new product: POST /api/products 4. Update a product price: PUT /api/products/501 5. Delete a product: DELETE /api/products/501 These endpoint URLs represent resources in a predictable and user-friendly way.

Best Practices for Designing RESTful APIs:

If you want to build an API for production and that is Google friendly, then you need to follow these Best Practices: 1. Do not use verbs, only nouns in your endpoint URLs. 2. Always return appropriate HTTP status codes. 3. Have Stateless APIs. 4. When dealing with large sets of data use pagination. 5. Secure your API's using JWT and OAuth. 6. Always Version Your API, Example /api/v1/products Differentiating between REST API and RESTful API allows developers to build better and more scalable applications for a quicker, more efficient experience when building larger systems effective for coding. A developer’s future in coding requires an understanding of RESTful APIs (e.g. Java, JavaScript, Node.js, React or Back End Development), especially if that will be a part of the developer's career after 2026. A well-designed API connects different systems as well as builds the base to enhance modern digital experience with those systems.