Backwards compatible - Definition and Overview

The term backwards compatible refers to the ability of a recent software or hardware components to be able to work with earlier versions of the same product.

For example, the Intel line of microprocessors that includes the Pentium series has maintained backwards compatibility with the earliest 8080/86 versions that were introduced over 20 years ago. This practice allows software investments made with an earlier processor in mind to remain viable with later ones.

In contrast, games consoles have traditionally sacrificed backwards compatiblity to improve performance. Sony went against the trend by designing the PlayStation 2 to be able to run PlayStation games. It is not yet clear if the Xbox Next will be able to run games written for the Xbox.

Early documents produced by Microsoft Word that were once readable by later versions are now orphaned since the latest versions found that retaining compatibility would have inhibited future capabilities.