What is an error?

Errors in the design/implementation process
- Due to a wrong decision at an early point in time - a mental flaw
Errors in the source program
- Illegal use of the programming language
- Erroneous implementation of an algorithm
Errors in the program execution - run time errors
- Exceptions - followed by potential handling of the exceptions

Errors in the development process may lead to errors in the source program.

Errors in the source program may lead to errors in the running program