This document discusses fundamentals of software testing. It begins with definitions of software testing and its objectives such as finding defects, gaining confidence, and preventing defects. An analogy is made between software testing and driving tests, where the tester is like the driving examiner. The document then discusses different types of testing, focusing on defects to help plan tests, and how defect clusters change over time. It also covers debugging, and how finding any defects shows that the software is not completely bug-free. The key purpose of testing discussed is to find issues and improve quality.