Question - What is the difference between functions and actions in QTP?
Answer -
Actions have their own Object Repository & Data Table. Actions help make your Test modular and increase reuse. Example: You can divide your script into Actions based on functionality like Login, Logout etc.
Functions is a VB Script programming concept and do not have their own Object Repository or Data Table. Functions help in re-use of your code. Ex: You can create a Function in your script to concatenate two strings.