Final answer:
A portable system, according to Schach, is a computer system that can be easily transported or carried around. It is typically small, lightweight, and can operate on battery power. An example of a portable system is a laptop computer.
Step-by-step explanation:
According to Schach, a "portable" system is defined as a computer system that is capable of being easily transported or carried around. This typically involves having a small and lightweight design, as well as being able to operate on battery power. A good example of a portable system is a laptop computer, which can be easily moved and used anywhere.