CS1 Course Site       Compilation of Powerful Ideas ( Cognitive and Computational ) Top 10 list of Powerful Ideas Commands and Operators   Commands and Operators are both equally powerful ideas. A command is a program that performs an action (other than returning a value). An operator is a program that returns a value. They allow easy manipulation of variables.   They also simplify the programs they are being used in much in the same way as a class,  because once they have been written they can be used over and over again.   They save space in programs sinse they only have to be written once.   If you didn't have Commands and Operators,  everytime you wanted to preform the task that a command or operator would be written for,  you would have to write lines upon lines of code to do the job.