Bug tracking is the process you use to address programming errors found. This process includes recording the bug, reviewing it, recording the fix needed, and deciding whether or not the bug will be fixed considering budget and schedule. Keeping good records of decisions made will help to control the scope of the project. Bug tracking also enables you to know what was done with identified issues, why the system was changed, and what future changes to consider.
From : www.epri.com/eprisoftware/processguide/glossary.html