Test Plan , Test Strategy is almost the same. it actullay 
tells how a testing activity has to be carried out in terms 
of people, tools, procedure and support.
in some of the cases , Test plan covers test strategy

Test plan covers the bellow:
1. Introductin
2. Objectives and task
3. scope
4. Test strategy
   1. Unit test
   2. Integration test
   3. System test
   4. Regression / retest
   5. Alpha test
   6. Beta test
   7. UAT
5. Hard ware requirements
6. Software requirements
7. Environment requirements
   1. Main frame
   2. workstation

8. Features to be tested
9. features cannot be tested
10. No. of resoruces
11. Resources roles and responsibilities
12. schedules
13. dependencies
14. risk
15. tools
16. approvals