Explain Test Plan, Test Strategy, Test Scenario, Test Case, Test Script, Test Environment, Test Procedure and Test Log.

Test Plan is a document with information about Scope of the project, Approach, Schedule of testing activities, Resources or Manpower required, Risk Issues, Features to be tested and not to be tested, Test Tools and Environment Requirements.
Test Strategy is a document prepared by the Quality Assurance Department with the details of testing approach to reach the Quality standards.
Test Scenario is prepared based on the test cases and test scripts with the sequence of execution.
Test case is a document normally prepared by the tester with the sequence of steps to test the behavior of feature/functionality/non-functionality of the application.
Test Case document consists of Test case ID, Test Case Name, Conditions (Pre and Post Conditions) or Actions, Environment, Expected Results, Actual Results, Pass/Fail.
The Test cases can be broadly classified as User Interface Test cases, Positive Test cases and Negative Test cases.
Test Script is a program written to test the functionality of the application. It is a set of system readable instructions to automate the testing with the advantage of doing repeatable and regression testing easily.

Test Environment is the Hardware and Software Environment where the testing is going to be done. It also explains whether the software under test interacts with Stubs and Drivers.
Test Procedure is a document with the detailed instruction of step by step execution of one or more test cases. Test procedure is used in Test Scenario and Test Scripts.
Test Log contains the details of which test cases were run with the output of execution.