So What is Bugzilla?

If you are looking for an open source Bug tracking system, Bugzilla falls under this category…

Bugzilla is a “Defect Tracking System” or “Bug-Tracking System”. Defect Tracking Systems allow individual or groups of developers to keep track of outstanding bugs in their product effectively

Bugzilla Review
Bugzilla, though with a poor interface design, is a feature rich tool covering most of the requirements for defect management. Though there are other existing systems that I think is better than Bugzilla, It is still widely used by different companies as stated on their website

Bugzilla is kinda flexible allowing you to define multiple products which in reality could be treated as multiple projects. It can group bugs or defects into several components which can be treated as sub systems of modules of a particular project…