What are the three modes of running the scripts?

WinRunner provides three modes in which to run tests: Verify, Debug, and Update. You use each mode during a different phase of the testing process.
Verify
Use the Verify mode to check your application.
Debug
Use the Debug mode to help you identify bugs in a test script.
Update
Use the Update mode to update the expected results of a test or to create a new expected results folder.