The concept of a wrapper is taken from a wrapper function that is used in programming for convenience of using other modules of code - .
For open hardware, a wrapper may be thought of as "an interface to an interface". In other words, if no clear way exists for connecting two hardware modules or components - then an intermediary piece of hardware may be used to make the connection.
For maximizing modularity, modules should have interface standards for universal interconnectability. Likewise, wrappers should follow universal standards to maximize interoperability.