The three basic patterns of logic that express a problem solution.

Represents the computer’s ability to execute instructions in a step-by-step, sequential manner.

Represents the computer’s ability to make a decision.

Represents the computer’s ability to repeat a series of instructions

Describes the sequence of steps between the actor (user) and the system necessary to complete a goal. Includes the alternate ways to complete a goal.

The functions that the software/system is intended to perform, and what the software should do (behaviors) given conditions.