Software testing is a process of evaluating an application to ensure it meets customer requirements. Testing verifies the application functions as intended and identifies any errors or defects. It should begin early in the development process during requirements analysis to find issues quickly and reduce costs. An effective testing approach includes creating a test plan, writing test cases, executing tests against the application, reporting results, releasing to production, and ongoing maintenance testing. The overall goal of software testing is to deliver a high quality product that satisfies customers and grows the business.