Interface
Interfaces are implemented
Interfaces cannot have constructors
Multiple interfaces can be implemented(thereby allowing multiple inheritance)
Interfaces can only contain abstract methods or functions
all the members of an interface are public by default and cannot be explicitly declared so
All the methods/functions of an interface must be impelmented


Abstract Class
Abstract classes are Inherited
Only a single class can be inherited
Abstract classes can have both abstract and contrete methods
All the abstract members of an Abstract Class must be declared public
All the abstract methods/functions of an Abstract class must be implemented