The document discusses test case structure and provides an example of a test case with the following key elements: 1) It defines a test case as a set of test inputs, execution conditions, and expected results to exercise a specific program path or requirement. 2) It outlines the typical sections of a test case including general information, activities, inputs, and expected vs. actual results. 3) It provides an example test case to verify an error message appears when invalid values are entered.