In SDLC, the bug has a life cycle. The bug should go through the life cycle to be closed.
Bug life cycle varies depends upon the tools used and process followed in the organization.
Some Well known bug tracking tools are QC, JIRA etc.
During a bug life cycle a bug has different status-
1.New- When a tester finds a bug then the status of that bug is "NEW"
2.Assigned- If the bug found by the tester is valid then it will be assigned to development team and its status become "ASSIGNED".
3. Open -When developer starts working on assigned bug its status become "open".
4. Fixed- When developer doses necessary code changes and unit tested the bug after verification by developer the status will become "FIXED"
5.Test- When an issue is fixed and assigned to tester then status will come "TEST"
6. Verified- When issue is tested by tester and found working fine then status of that bug become "VERIFIED"
7. Closed: After verified the fix, if the bug is no longer exits then the status of bug will be assigned as “Closed.”
8.Reopen: If the defect remains same after the retest, then the tester posts the defect using defect retesting document and changes the status to “Reopen”. Again the bug goes through the life cycle to be fixed.
9.Duplicate: If the defect is repeated twice or the defect corresponds the same concept of the bug, the status is changed to “duplicate” by the development team.