A test plan is a document that describes the scope, 
approach, resources, and schedule of intended testing 
activities, while a test scenario is a document that 
describes both typical and atypical situations that may 
occur in the use of an application.

Test scenario:In test sceanario ewe jst use black box 
testng dat is we jst calculate the boundary values nd 
equivalence class partitions nd depending on the 
specification some times we use decision tables.

Test case:test case is a group of steps dat is to be 
executed to check the functionality of specific object.In 
testcase test engineers are prepare testcase documents 
using IEEE 829 format.