A test case is a documentation which specifies input values, expected output and the preconditions for executing the test.
Test case is How To Be Tested
IEEE Standard 610 (1990) defines test case as follows:
A set of test inputs, execution conditions, and expected results developed for a particular objective, such as to exercise a particular program path or to verify compliance with a specific requirement.
Test Case Template
A test case can have the following elements. Note, however, that normally a test management tool is used by companies and the format is determined by the tool used
Test Case Field Description