Difference between abstract class and interface

A class implementing an interface must implement all of the

methods defined in the interface, while a class extending an
abstract class need not implement any of the methods defined
in the abstract class. Additionally, a class extending an
abstract class can implement an infinite number of it's own
methods.

another key difference between abstract class and interface
is that , in abstract class we can put sharable code, but
that is not possible in case of interface.

Another key difference between abstract class and interface
is that,

We can use interface as marker, ( we can use abstract class
also as abstract but then we can't extends any oter class,
so it is better always use interface as marker)

Marker===> An interface having no methods is called as a
Marker Interface।


In abstract class aleast one method must be abstract(only
declared not define).we can create object of abstract class.
if we want to use this class then we have to inherit it.


In interface all the method must be abstract(only define).
using interface we can achieve multiple inheritence.
we use interface where one class cannot extend more than


and in Inheritance all methods should be abstract.means not
defined..but where as in Abstract class methods can be both
Abstract n defined...but one of the method should be Abstract.
one class(in java).