FAQ: What is the definition of a system?
Date: 27 Sep 04
Answered by: Asa Hopkins
Very generally, a system is something that can be placed in a physical or metaphorical "box". Slightly more concretely, we might consider a system to be a single object or interacting collection of objects with some number and type of inputs, and some number and type of outputs. We will be most interested in dynamical systems (those which change over time or whose outputs change over time).
Whether something is a system or not depends on what interests you about it. From a dynamical perspective, a fixed, stationary metal block might not be very interesting, with no obvious inputs or outputs, and therefore wouldn't make a good system. However, if we're interested in thermal or electrical properties, it might be an interesting system.