@Dharmendra Gauryou are absolutely right......
Traceability Matrix is used in bothe the SDLC and Testing QA.
please refer this link for Traceability.
http://www.jiludwig.com/Traceability_Matrix_Structure.html
Traceability matrix is used to map between requirements and test casesit is used to check all requirements are covered or not?
Tracabilty Matrix is a document which is used to Map the UseCase and testcases.i.e.it shows the full usecase on one side and names the respective testCases in which the flows of that usecase are covered.