in this case, an abstract method is a special type of method without any implementation. it only declares the method signature, and the implementation details are left to the subclass implementation. use abstract methods to create an abstract class, which contains unfinished implementation details. characteristics of abstract classes abstract class must contain at least one abstract method, and the abstract class must contain at least one abstract method. there is no implementation. the abstract method cannot have a body. the abstract method has no method body. braces. the abstract method must be overwritten. in the subclass, all... video,movie