What is a State Machine Diagram?

A state diagram is used to represent the condition of the system or part of the system at finite instances of time. It’s a 
behavioral diagram and it represents the behavior using finite state transitions. 

• State Machine diagrams are also referred to as State Diagrams and State-Chart Diagrams.
• These terms are often used interchangeably. So simply, a state machine diagram is used to model the dynamic behavior of a class in response to time and changing external stimuli. 

State Machine Diagrams and Activity Diagrams are two types of behavioral diagrams in UML (Unified Modeling Language) used to model the dynamic aspects of a system. While both diagrams depict the flow of control in a system, they serve different purposes and are used in different contexts. This article explores the key differences between State Machine Diagrams and Activity Diagrams, their use cases, and how they contribute to the overall understanding of a system’s behavior.