A test automation platform is a tool or a framework that makes it easy to automate software testing. It uses programs and scripts that are written by developers or testers to automate the entire process.
A test automation platform typically provides all the functionality that you would need to start with automated testing. It saves you from using a plethora of tools and makes them work with each other.
Test automation platforms primarily find their use in complex or large software projects where it’s difficult or cumbersome to perform manual testing on all the functionality provided by the software.