A **State Chart** (or **State Machine Diagram**) is a visual representation of a system's states and the transitions between them. It is commonly used in software engineering, systems design, and modeling to describe the behavior of complex systems. Each **state** represents a condition or situation in the lifecycle of an object, and **transitions** indicate how the system moves from one state to another in response to events. ## Traffic Light State Chart in Mermaid ```mermaid stateDiagram-v2 [*] --> Red Red --> Green : Timer Expired Green --> Yellow : Timer Expired Yellow --> Red : Timer Expired ``` Key components of a State Chart include: 1. **States**: These are the various conditions an object or system can be in. For example, in a media player, the states might include "Playing," "Paused," and "Stopped." 2. **Transitions**: These are the paths between states, usually triggered by some event or condition. For example, transitioning from "Paused" to "Playing" might occur when the user presses the "Play" button. 3. **Events**: An event triggers a transition from one state to another. It could be a user action (like a button press) or an external event (such as a message received). 4. **Initial State**: The state in which the system starts when it is first created or initialized. 5. **Final State**: The end state that indicates when the system has completed its work or the object’s lifecycle has ended. 6. **Actions**: These are activities or operations that occur in response to transitions or while a system is in a particular state. State charts are commonly used in software design to model dynamic behavior and control the flow of logic, especially in event-driven systems or user interfaces. They help visualize how different states relate to one another, making the system easier to understand and maintain. In Next.js projects using libraries like **[[XState]]**, State Charts can be used to manage application state efficiently, ensuring a clear and maintainable flow between different states of the app. # References ```dataview Table title as Title, authors as Authors where contains(subject, "State Chart") sort title, authors, modified ```