Computer programming involves designing, writing, testing, debugging, and maintaining source code to create a program that exhibits desired behaviors. There are three main types of programming errors: syntax errors due to incorrect language usage, logic errors involving flawed program design, and arithmetic errors from inappropriate mathematical operations like division by zero. Testing is the process of executing programs to find errors and ensure requirements are met. It helps improve quality, verify functionality, estimate reliability, and validate exceptional handling. Alpha and beta testing involve simulated or limited real-world use before public release. Black box testing examines external functions without viewing internal structures, while white box testing uses internal knowledge to design test cases. Interface testing verifies connections between components.