Software testing is the process of evaluating and verifying that a software product or application does what it's supposed to do. The benefits of good testing include preventing bugs and improving performance. Verify and validate application quality to ensure it meets user requirements.

software testing is the process of assessing the functionality of a software program. The process checks for errors and gapes and whether the outcome of the application desired expectations before the software is installed and goes live.
system software
program software
application software
the three types are software testing.

Application software:
Mobile based application. Use all your web application. front and code programming language.Ex:f12,google, you can see application you need correspond back and code language also an application mode. Ex: python, java