How do abstraction and inheritance solve different problems?

Abstraction describes the capabilities a caller needs without exposing every implementation detail. A payment interface might offer charge and refund operations. Inheritance creates a subtype relationship that can also share implementation. A card payment and a wallet payment may implement the same abstraction without inheriting from a common concrete class. Use abstraction to define a stable contract; use inheritance only when the subtype can honor the parent’s behavioral promises. Sharing a few similar methods is not enough reason to create an inheritance hierarchy.