Troubleshooting : – It is done when a software or hardware do not perform well, in this a series of steps are performed in order to fix the issue. It may require hardware or software troubleshooting.

Testing :- It is performed by a tester or some specific users. It is the precursor to debugging. Here a product or software is tested on different parameters that the product is all ready to be launched in the market or not. Testing is also done when an update of the product is also launched. In this case the testers are responsible only to find the “Bugs” and report them to the developers team.

Debugging : – It is something which a programmer and developers are supposed to deal with. Under this a developer does the fixing of codes and some of the debugging tools are used in it. It is all associated with software errors not hardware.