Swagger2 is an open source project used to generate the REST API documents for RESTful web services. 

It provides a user interface to access our RESTful web services via the web browser.

To enable the Swagger2 in Spring Boot application, you need to add the following dependencies in our build configurations file.

https://www.tutorialspoint.com/spring_boot/spring_boot_enabling_swagger2.htm

Swagger is being used to share documents among developers, testers, and product managers, as well as to automate API-related tasks through various technologies. OpenAPI Specification (OAS), which includes both open source and professional tools, is also utilized in the development of APIs.

Swagger also assists in defining the structure of our APIs so that machines may read them. It accomplishes this by requesting that our API return JSON or YAML including a full description of our API. The major Swagger tools include:

Swagger Editor—- It is a browser-based editor for writing OpenAPI specifications.

Swagger UI—- Creates dynamic API documentation from OpenAPI specifications.

Swagger Codegen—- from an OpenAPI specification, it creates server stubs and user libraries.

https://mindmajix.com/swagger-interview-questions#why-use-open-api