Abstraction is a process of hiding the implementation details and showing only functionality to the user. An abstract class can never be instantiated. If a class is declared as abstract then the sole purpose is for the class to be extended.

abstract class Car
{
    abstract void tagLine();
}
 
class Honda extends Car
{
    void tagLine()
    {
        System.out.println("Start Something Special");
    }
}
 
class Toyota extends Car
{
    void tagLine()
    {
        System.out.println("Drive Your Dreams");
    }
}