An architectural style defines as a family of such systems in terms of a（ ）of structural organization．More specifically， an architectural style defines a vocabulary of （ ）and connector types， and a set of （ ） on how they can be combined. For many styles there may also exist one or more （ ）that specify how to determine a system’s overall properties from the properties of its parts．Many of architectural styles have been developed over the years.
The best-known examples of（ ）architectures are programs written in the Unix shell.
