noun
compatibility; interchangeability
Technical term used in engineering, computing, and standards contexts to describe the ability of components, systems, or formats to work together or be substituted for one another.
このソフトウェアは古いバージョンとの互換性がありません。
This software is not compatible with older versions.
部品の互換性を確認してから注文してください。
Please check the compatibility of the parts before ordering.
適合性 means 'conformity' or 'suitability', focusing on meeting standards or requirements, while 互換性 emphasizes mutual substitutability between two or more items.
Compound of 互換 (interchange) + 性 (property/quality). 互換 is itself a compound of 互 (mutual) and 換 (exchange). The term is a relatively modern coinage for technical 'compatibility'.