Editing Forward compatibility (section)

{{short description|Design characteristic that allows a system to accept input intended for a later version of itself}}

'''Forward compatibility''' or '''upward compatibility''' is a design characteristic that allows a [[system]] to accept [[Input/output|input]] intended for a later [[software versioning|version]] of itself. The concept can be applied to entire systems, electrical [[User interface|interface]]s, [[telecommunication]] [[signals]], [[data communication protocol]]s, [[file format]]s, and [[programming language]]s. A [[technical standard|standard]] supports forward compatibility if a [[product (business)|product]] that complies with earlier versions can "[[graceful exit|gracefully]]" process input designed for later versions of the standard, ignoring new parts which it does not understand.

The objective for forward compatible technology is for old devices to recognise when data has been generated for new devices.<ref name=Tulach>{{cite book|url=https://books.google.com/books?id=DXYZZVlWOAkC&pg=PA233|title=Practical API Design: Confessions of a Java Framework Architect|first=Jaroslav|last=Tulach|publisher=Apress|date=2008|isbn=978-1-4302-0973-7|page=233}}</ref>

Forward compatibility for the older system usually means [[backward compatibility]] for the new system, i.e. the ability to process data from the old system; the new system usually has ''full'' compatibility with the older one, by being able to both process and generate data in the format of the older system.

Forward compatibility is not the same as [[extensibility]]. A forward compatible design can process at least some of the data from a future version of itself. An extensible design makes upgrading easy. An example of both design ideas can be found in web browsers. At any point in time, a current browser is forward compatible if it gracefully accepts a newer version of [[HTML]], whereas how easily the browser code can be upgraded to process the newer HTML determines how extensible it is.