Abstract (summary) , an abbreviated summary of any in-depth analysis of a particular subject or discipline
Abstract (law) , a brief statement of the most important points of a long legal document or of several related legal papers
Abstract Structure , a set of rules, properties and relationships that is defined independently of any physical objects
Abstract Class , a class in object-oriented programming that is designed only as a parent class and from which child classes may be derived, and which is not itself suitable for instantiation
Abstract Art , art that does not depict objects in the natural world
Abstract Hip Hop , a subgenre of alternative hip hop distinguished principally on the content of the lyrics