Definition of Abstraction. a concept or idea not associated with any specific instance; "he loved her only in the abstract--not in person". the act of withdrawing or removing something. the process of formulating general concepts by abstracting common properties of instances.

And the difference between abstract and interface is a hairsplitting thing when you have duck typing. Java uses interfaces because it doesn't have multiple inheritance. Because Python has multiple inheritance, you may also see something like this