Difference between abstract class and interface in php

S.No	Abstract Class	Interface Class
1	Abstract class - method must be declared as abstract. Abstract methods doesn’t have any definition. The sub class (extend class) can have the definition for those abstract method.	Interface - all the methods by default are abstract methods only. So one cannot declare variables in interfaces. The sub class (implement class) can have all method definition for those methods.
2	The Abstract methods can declare with Access modifiers like public, internal, protected.	All methods declared in an interface must be public.
3	Abstract class can contain variables and concrete methods.	Interfaces cannot contain variables and concrete methods, but we can possible to define the constants.
4	An abstract class can Inherit only one Abstract class and Multiple inheritance is not possible for Abstract class.	A class can implement many interfaces and Multiple interface inheritance is possible.