Difference Between Web API and REST API

Feature	Web API	REST API
Definition	A framework for building HTTP-based services in .NET Core or other technologies.	A set of architectural principles for designing stateless, resource-based APIs.
Protocol	Can work over HTTP, TCP, or other protocols.	Strictly works over HTTP.
Architecture	Can follow REST, SOAP, or other communication styles.	Strictly follows RESTful principles.
Data Format	Can return JSON, XML, or other formats.	Typically returns JSON, but can support XML as well.
State Management	Can be stateful or stateless.	Stateless (Each request is independent).
Methodology	Based on ASP.NET Core, WCF, or other technologies.	Follows CRUD operations using standard HTTP methods.
Use Case	Used for building APIs for various communication styles.	Used for creating scalable, resource-oriented web services.

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Example to Clarify the Difference

• A Web API can be RESTful, but it can also be SOAP-based or use different communication protocols.
• A REST API always follows REST principles, using HTTP for communication.

Example of a Web API (Non-RESTful)

A SOAP-based API in ASP.NET Core:

<soap:Envelope>
    <soap:Body>
        <GetProduct>
            <Id>1</Id>
        </GetProduct>
    </soap:Body>
</soap:Envelope>

Example of a REST API

A RESTful API using HTTP:

GET /api/products/1 HTTP/1.1
Host: example.com

Response:

{ "id": 1, "name": "Laptop", "price": 50000 }

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Key Takeaway

• If you build an API in .NET Core, it is called a Web API.
• If your Web API follows REST principles (stateless, resource-based, uses HTTP methods like GET, POST, PUT, DELETE), then it is also a REST API.