In TypeScript, access modifiers are keywords used to control the visibility and accessibility of class properties and methods. There are three access modifiers in TypeScript:

• public: This is the default access modifier. Properties and methods declared as public can be accessed from anywhere, both inside and outside the class.
• private: Properties and methods declared as private can only be accessed within the same class. They are not accessible from outside the class.
• protected: Properties and methods declared as protected can be accessed within the class and its subclasses. They are not accessible from outside the class and its subclasses.

Access modifiers in TypeScript allow you to define the level of visibility and accessibility of properties and methods in your class, making your code more maintainable and secure.