• Props: Short for properties, props are used to pass data from a parent component to a child component. They are immutable and primarily used for communication between components.
• State: State represents the internal data or variables of a component that can change over time. Unlike props, the state is mutable and managed within the component.

React Router provides routing capabilities, enabling developers to create single-page applications (SPAs) with dynamic navigation. Advantages include:

• Seamless navigation without full page reloads.
• Declarative routing for better code readability.
• Nested routing for complex UI structures.
• Easy handling of URL parameters and query strings.

To optimize React applications:

• Use React.memo to prevent unnecessary re-renders.
• Use lazy loading and code splitting to reduce initial load time.
• Minimize stateful components and avoid deep component trees.
• Leverage the useCallback and useMemo hooks for performance.
• Keep components small, reusable, and focused on a single responsibility.
• Monitor and optimize rendering using tools like React DevTools and Profiler.