Compatibility may refer to: Computing Backward compatibility, in which newer devices can understand data generated by older devices Compatibility card, an expansion card for hardware emulation of another device Compatibility layer, components that allow for non-native support of components Compatibility mode, software mechanism in which a software emulates an older version of software Computer compatibility, of a line of machines IBM PC compatible, computers that are generally similar to the original IBM PC, XT, or AT Hardware compatibility, between different pieces of computer hardware License compatibility, of software licenses Pin compatibility, in devices that have the same functions assigned to the same particular pins Software compatibility, between different pieces of software Software incompatibility Science and mathematics Compatibility (biological), a property which is assigned to splits of a given set of taxa Compatibility (chemical), how stable a substance is when mixed with another substance Compatibility (geochemistry), how readily a particular trace element substitutes for a major element within a mineral Compatibility (mechanics), the study of compatible deformations in continuum mechanics Electromagnetic compatibility, which studies the unintentional generation, propagation, and reception of electromagnetic energy Consistency, logical compatibility between two or more propositions Compatible relation, a binary relation that commutes with each operation of an algebraic structure Other uses Astrological compatibility, a branch of astrology that studies relationships by comparing natal horoscopes Compatibilism, a philosophical position Interpersonal compatibility, the long-term interaction between two or more individuals in terms of the ease and comfort of communication