Explain the difference between structural and nominal typing systems.

Structural typing compares type structure, while nominal typing compares type names. TypeScript uses structural typing. Structural Typing (TypeScript): interface Point2D { x: number; y: number; } interface Vector2D { x: number; y: number; } // These are compatible due to same structure let point: Point2D = { x: 1, y: 2 }; let vector: Vector2D = point; // OK in TypeScript Nominal Typing (Languages like Java/C#): // In Java, these would be different types class Point2D { int x, y; } class Vector2D { int x, y; } // Point2D point = new Vector2D(); // Error in Java TypeScript Duck Typing: function drawPoint(point: { x: number; y: number }) { console.log('Point at (' + point.x + ', ' + point.y + ')'); } // Any object with x and y properties works drawPoint({ x: 1, y: 2 }); // OK drawPoint({ x: 1, y: 2, z: 3 }); // OK (extra properties allowed) Implications: • Structural typing enables duck typing • More flexible but can allow unintended compatibility • Nominal typing is more strict but verbose • TypeScript approach enables JavaScript interoperability.