Feature Image Article 5 key differences between API and Rest API

5 Key Differences between API and REST API

By Laurent Mauer · July 26, 2022 · 12 min read

APIs are the building blocks of the Internet. They allow developers to take the data from one platform and use it on another one.

There are many types of APIs, but we will focus on two in this article: REST API and API.

There is a lot of confusion around the differences between API and REST API, so I decided to write this blog post to clear up some of that confusion.

We’ll also look at some of their key differences.

API: Intro 101

Let’s dive into the concepts, definitions and specifications of one of the best things in modern programming.

What is an API?

API stands for Application Programming Interface.

An API is a set of functions and procedures that software developers use to build applications.

You can think of it like a library where you can take what you need and leave the rest behind.

Types of API

  • Web API

A web API is a software that allows for the creation of apps and tools by external developers.

It does this by providing a set of functions and methods that can be called remotely over HTTP and HTTPS.

The idea behind web APIs is to enable third party developers to build applications on top of your service or product.

These applications might be mobile apps, websites, or desktop software.

  • Remote API

A remote procedure call (RPC) is a mechanism for invoking a function on a remote computer.

The function to be invoked is encoded in an arbitrary format, often by means of some encoding scheme.

The encoded request is then sent over a network to the server. The server decodes the request, invokes the named function, and encodes the result before returning it to the client.

Remote Procedure Calls (RPCs) are used by distributed systems to invoke procedures on one or more other machines. They are a form of inter-process communication.

RPCs are typically used when:

    • The code that needs to be executed resides on another machine (e.g., web service).
    • There are multiple instances of the same running code that need to communicate with each other and want to minimize latency between them by executing on the same machine (i.e., intra-process RPC).
  • Public API

These APIs can be used by anyone. This can be accessed over the Internet and you don’t need any special permission to use these APIs.

  • Private API

These APIs can be used only by authorized users who have access to them. You will need an authorization token to use these APIs.


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API Architecture and protocols


JSON-RPC is a remote procedure call over HTTP.

It allows you to invoke methods of a remote server, with the arguments and results encoded in JSON.

JSON-RPC was originally created by Brad Fitzpatrick as a lightweight alternative to SOAP, XML-RPC and other RPC systems.

It was designed to be simple, more efficient than XML, and easily extended.

The JSON-RPC specification defines two message formats:

    • Request messages can contain method names and parameters (inputs) for a function call. The request message may also include an identifier for the client that generated the message. A request can also include an id parameter that identifies the request to be acknowledged by the server.
    • Parameters are sent as key/value pairs within a single object, where each parameter is represented as a name/value pair separated from other parameters by a comma (“,”). When sending multiple parameters in one request, they should be separated by commas as described above – this is because some languages such as JavaScript do not allow spaces within an object literal.

Response messages can include status codes indicating error conditions, which include “code”: 300


XML-RPC is a remote procedure call (RPC) protocol that uses HTTP as its transport. It has been implemented in a number of languages, and client libraries exist for many more.

XML-RPC is actually a subset of SOAP, which defines the XML format and processing rules for messages exchanged between two computers.

The RPC calls use XML formatted messages to exchange arguments and return values between client and server applications.

The arguments are encoded in the body of the message while return values are encoded in the HTTP header section or content type “application/xml”.

A typical request looks like:

 <?xml version=”1.0″ encoding=”UTF-8″?>





  • SOAP (Simple Object Access Protocol)

A SOAP API (Simple Object Access Protocol) is a standardized way to send and receive data across the Internet.

It allows for remote access to information and functionality through a web service.

The SOAP protocol uses XML to define the structure of messages that are transmitted between an application and its clients or servers.

SOAP messages can be sent over HTTP, SMTP, TCP/IP, or any other protocol that supports HTTP methods (GET/POST).

  • REST

REST stands for Representational State Transfer, which is an architectural style for building scalable web services.

RESTful APIs use HTTP verbs (like GET, PUT and DELETE) to make requests against resources on the server.

A RESTful API uses hypermedia links to define how data should be accessed, transformed or manipulated in real-time.

  • GraphQL

GraphQL APIs use GraphQL queries and mutations to retrieve data from a database or other source.

In a GraphQL API, you’re able to define the exact data you want from the server, and nothing more.

GraphQL is a query language for APIs that was developed by Facebook and released as open-source software in 2015.


The idea behind GraphQL is that instead of having multiple endpoints for each resource, you can have one endpoint (or URL) and ask for exactly what you need at that point in time.

This is done by sending a query string with your request where it will be parsed by the server and returned as JSON or XML.

GraphQL has many benefits over REST APIs, including:

  1. Flexible data requirements: You can specify exactly what data you need and only that data will be returned instead of having to make several requests to get just what you want.
  2. Efficient data usage: Data is sent only when required, saving bandwidth and increasing performance by reducing unnecessary roundtrips between client and server.
  3. Versioning support: If your API changes over time, your clients will not break because they know what version of the API they are using at any given time thanks to a query parameter in their requests.
  4. Strongly typed APIs: You don’t need to worry about casting strings

5 Key Benefits of API

The benefits of using an API are many but some of them are the following:

  • It provides a single point of contact for all your business needs.
  • It allows you to focus on your core competencies while outsourcing non-core tasks to external service providers at lower costs.
  • It helps you to reduce development and maintenance costs by providing an interface between different applications built by different vendors or organizations.
  • It helps in reducing development time and cost as it is easier to integrate new features into existing systems than develop a new application from scratch every time.
  • It enables businesses to benefit from economies of scale by reusing assets across products and services, thus lowering the cost per unit for each new product or service launched by them.

5 Key Differences between API and REST API

Stateless vs Stateful

Stateless APIs don’t store any information about previous requests.

Each request is a standalone entity. Concretely, a stateless API doesn’t keep track of any information about a client, so it cannot serve a cached response. 

For example, if you make a GET request to https://api.github.com/users/octocat/, the server will return all of the information about Octocat’s account.

If you make a POST request to https://api.github.com/users/octocat/, the server will return all of the information about Octocat’s account again (not just the information that changed).

Stateful APIs store some information about previous requests so that they can be reused on future requests.

It must maintain state between requests because it’s processing information over time.

This makes it possible for the API to cache data and return results using less bandwidth and fewer server resources.

For example, if you make a GET request to https://api.github.com/users/octocat/, the server won’t return all of the information about Octocat’s account since this may be too much data to send over the Internet connection between your computer and GitHub’s servers.

Instead, it will only return enough data for you to be able to see what has changed since your last visit (“last visit” being defined as the last time you made an HTTP request to that URL).

Methods/Protocol: HTTP vs Web Services

HTTP is a protocol that was developed to allow computers to communicate with each other.

It is a request/response protocol and can be used for many different applications, such as retrieving information from a database or uploading images to a website.

It also allows for authentication and cookies, which make it possible for browsers to handle multiple requests at once without having to re-authenticate with each one.

REST APIs have become so popular that some people use the terms “REST API” and “Web API” interchangeably, but they’re not the same thing!

A web API lets you interact with a web server through HTTP requests, while a REST API lets you interact with any kind of server over HTTP.

REST APIs are web services that use HTTP and provide an interface for clients to interact with the service.

They can be used to retrieve data or perform actions, such as creating records or updating existing ones.

Web services are designed to make it easy for people to share data and functionality between applications.

They are not limited to one programming language or platform, so you can use them with almost any application.

How do they work?

Web services use open standards like XML (Extensible Markup Language) and SOAP (Simple Object Access Protocol). 

These standards define how data is formatted and transmitted over the Internet.

A typical web service request looks like this: http://abcdefg12345678901234567890/myService?method=getMessage&input=foo&output=bar.

Operations type: CRUD vs PUT, POST, DELETE

CRUD stands for Create, Read, Update and Delete.

These are the four basic functions that all APIs should support: 

  • CreateThis is typically used to create a new resource.

The Create operation is used to create a new resource or object.

In the Create operation, you have to provide the name of the resource and its properties.

For example, you can create a new product by sending a POST request with the following JSON payload:


“name”: “Product Name”,

“price”: “100”,

“sku”: “sku-1”,

“color”: “black”,

“category”: “electronics”,

“description”: “Product Description” }


  • Read: This is used to get an existing resource.
  • Update: This is used to update an existing resource with some new data.
  • Delete: This is used to delete an existing resource.

REST API use following operations:

  1. GET request is a basic method that is used to retrieve data from an API. This data can be in the form of a simple text file or a more complex JSON object. The main purpose of this operation is to get access to data. 
  2. PUT is used to update an existing resource by providing its ID in the URL. The request body contains the new values for the fields of the resource being updated.
  3. DELETE is used to delete a resource from storage by providing its ID in the URL. To do this successfully, you must also provide a valid reason for why you’re deleting it along with other information about why it should be deleted.
  4. POST is used to create a new resource by sending some data through an HTTP request body or via query string parameters or form data.


REST APIs are lightweight and simple to implement compared to other types of API such as SOAP (Simple Object Access Protocol) or XML-based web services like WSDL (Web Services Description Language). 

REST is based on the HTTP protocol which makes it easy to understand and implement by developers across platforms like iOS, Android, Windows Phone etc., while SOAP/XML based web services require special knowledge about XML parsing which is not easily available across all platforms (except Java).

Use cases

REST APIs are built on HTTP, which is a stateless protocol.

That means that each request from the client is independent of the previous ones, and the response will be returned without any consideration for what happened previously in the same session.

A good example of this is when you use an API to send a message to someone in a messaging app.

You send one request with all the information about your message, and you get back another response with all of their messages.

Some APIs do not have this limitation and can send multiple requests in one session (using webhooks), but most REST APIs are limited to one request per session.

You can think of this as being similar to how you would interact with a website: when you visit a website through your browser, it’s as if you’re starting a new session every time you click on something or fill out a form.

The site doesn’t remember anything from your last visit (unless it’s stored in cookies).


API is a broader term, whereas REST API is a specific sort of API found in mobile and cloud apps.

No API is without flaws, but novice developers struggle with REST API since it fails to retain session data.

Businesses have swiftly enhanced their user interfaces as contemporary APIs have evolved as a product that adheres to certain standards and audiences.

At RestApp, we have built the Data Activation Platform for modern data teams and designed our next-gen data modeling editor to be intuitive and easy-to-use.

If you’re interested in starting with your data journey, check out the RestApp website or book a demo.


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Laurent Mauer
Laurent Mauer
Laurent is the head of engineer at RestApp. He is a multi-disciplinary engineer with experience across many industries, technologies and responsibilities. Laurent is at the heart of our data platform.
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