Computers are fast, accurate and stupid.
"The computer keeps doing what I tell it
instead of what I meant!"
Computers only do what you tell them,
whether or not what you told them is what you meant.
Don't ever say,
"It must be right. The computer said so."
People put the data in. They can make mistakes.
Any hardware malfunction is unlikely to cause an error in the contents of user data. Since all operations use the same central processing unit and bus, almost any hardware error will crash the system immediately.
High School => College Level
The purpose of the source code examples is to let the students enter and edit the programs to run on the language, operating system and hardware they are using. The program text illustrates programming techniques and data structures in the order they could be presented in class, while the running programs show the variety of applications possible.