A Java Abstract Method is a method declared in an abstract class or interface with no implementation. It defines a contract that must be implemented by any subclass. Java Abstract Methods allow developers to define a structure while leaving the implementation details to subclasses. This feature was introduced in Java 1995 with Java 1.0, supporting Java's object-oriented principles of abstraction and inheritance.

https://docs.oracle.com/javase/tutorial/java/IandI/abstractmethods.html