Rest assured is free. And very popular. It just jar files and we can add to our project to test rest api.

Postman is another tool to just do manual testing of our apis. So before we start writing code for our apis in rest assured its always a good idea to do some manual testing in postman first.

Now to automate all the above tasks we did using postman like get,post,put,delete on a rest api we can use rest assured. In rest assured we can generate reports and also parameterize the all test steps i.e provide values from excel files.