What is a difference between SOAP and REST API?

To understand the difference between REST and SOAP APIs. First, we should get to know what is an API?

API stands for 'Application Programming Interface'. It provides a way to communicate 2 different software programs or applications to exchange information easily even if both the applications are developed in different languages. For example we have Make my trip.com, cleartrip.com which shows all the flight information for each individual airlines like Air India, Indigo etc. this is possible with the help of APIs calls. Here Indigo, Air India are exposing their flight and booking information to Make my trip and other channels using a single API calls.

How APIs work

APIs are made up of two related elements. The first is a specification that describes how information is exchanged between programs, done in the form of a request for processing and a return of the necessary data. The second is a software interface written to that specification and published in some way for use.

The software that wants to access the features and capabilities of the API is said to call it, and the software that creates the API is said to publish it.

Three basic types of APIs

APIs take three basic forms: private, public and partner

Private APIs, or internal APIs, are published internally for use by the company’s developers to improve its own products and services. Private APIs are not exposed to third parties.

Public APIs, or open APIs, are published publicly and can be used by any third-party. There are no restrictions on these APIs.

Partner APIs can only be used by specific parties with whom the company agrees to share data. Partner APIs are used within business relationships, often to integrate software between partnering companies.


Now, Look at the difference between SOAP and REST below:

SOAP

1. SOAP means “Simple Object Access Protocol”
2. SOAP is a standard based approach to develop web service.
3. SOAP supports multiple protocols like HTTP(s), JMS, FTP etc.
4. SOAP web services only work with POST method.
5. SOAP exposes web services which are based on a contract (wsdl) with a set of operations with XML based messaging structures.
6. SOAP can only work with XML format.

REST

1. REST means “Representational State Transfer”
2. REST doesn’t follow any specific set of standards.
3. REST supports only HTTP protocol.
4. RESTful web services support POST, GET, PUT and DELETE methods.
5. REST uses (generally) URI and methods like (GET, PUT, POST, DELETE) to expose resources.
6. REST allows different data formats like Plain text, HTML, JSON, XML etc. But the most preferred format for transferring data is JSON.