What is the difference between an accessor method and a mutator method?

Accessors must always use the return type 'void', while mutators do not.

A class can have many accessors but only one mutator.

An accessor provides the client access to data in the object, while a mutator lets the client change the object's state.

Accessors are methods whose code never changes, and mutators are methods where the programmer can change the code over time.

Accessors' names often begin with 'set', while mutators' names often begin with 'get' or $\text{'}$is$\text{'}.$