What Does Legacy Application Mean?

A legacy application is a software application that is considered obsolete, or that is based on technology that is older than a current standard.

Techopedia Explains Legacy Application

The term “legacy technology” can refer to applications, platforms, hardware setups, programming languages and other technologies that have been superseded by newer options. That said, much discussion around legacy applications and legacy technology revolves around updating what is used by a particular end user or enterprise client.