downward compatible; backward compatible; compatible with input or components intended for lower tier or older systems, versions, etc.; upward compatible; forward compatible; compatible with input or components intended for higher tier or later systems, versions, etc.
① 組み合わせるべき複数の部品（要素）の間で、お互いに置き換えることができる性質。また、その性質の程度。
upward compatible; forward compatible; compatible with input or components intended for higher tier or later systems, versions, etc.; downward compatible; backward compatible; compatible with input or components intended for lower tier or older systems, versions, etc.