Software testing involves several key activities: (1) defining test plans and cases to evaluate software attributes and capabilities, (2) executing tests to uncover errors manually or automatically, and (3) analyzing and reporting test results. The objectives of testing include finding errors, validating requirements are met, and ensuring quality. Testers, engineers, and quality assurance groups all perform various testing roles and activities throughout the software development lifecycle. Effective testing requires independence, planning, and understanding that complete testing is impossible due to risks and limitations of time and resources.