For a bug tracking software it is essential to have:

☛ Reporting facility - complete with fields that will let you provide information about the bug, environment, module, severity, screenshots etc.

☛ Assigning - What good is a bug when all you can do is find it and keep it to yourself, right?

☛ Progressing through the life cycle stages - Workflow

☛ History/work log/comments

☛ Reports - graphs or charts

☛ Storage and retrieval - Every entity in a testing process needs to be uniquely identifiable, the same rule applies to bugs too. So, a bug tracking tool must provide a way to have an ID, which can be used to store, retrieve and organize bug information.