It is a framework provided by Microsoft for writing HTTP services. There are many frameworks available to build HTTP based services. They follow a common guideline of international standardization but with different flavors.
For example, all framework must adhere to these status codes-
- 1xx – Informational Message
- 2xx – Successful
- 3xx – Redirection
- 4xx – Client Error
- 5xx – Server Error
- It is light weight and thus good for small devices also like tablets, smart phones.
- No tedious & extensive configuration like WCF REST is required.
- MediaTypeFormatter makes easy to configure your APIs response type in single line (JSON, XML and so on).
- IIS Hosting dependency is no more and it can be hosted in application too.
- Easy and simple control with HTTP features such as Caching, Versioning, request/response headers and its various content formats.
- It support content-negotiation (deciding the best response data format that client can accept).
For further info click on the link,
Basic Understanding On ASP.NET Web API