API testing refers to the process of testing Application Programming Interfaces (APIs), which are the interfaces through which software applications communicate with each other.

API testing involves verifying whether an API fulfills the functional, performance, and security requirements defined for it. It typically involves sending requests to the API, receiving responses, and validating that the responses meet the expected behavior.

API testing can be performed manually, using tools like cURL or Postman, or through automated testing frameworks that can simulate the interactions between the application and the API. The objective of API testing is to ensure that the API behaves as expected and is able to handle a variety of inputs and usage scenarios, thus enabling the application to perform optimally.


BY Best Interview Question ON 07 Apr 2023