These are words and phrases that scientists use when discussing how a given area operates and functions. As you can see, all of these factors are interrelated and interdependent. In a sense, that is the definition of system . In other words, they can be measured, weighed, touched, and counted. Components are usually measured in terms of numbers per area, like grams per meter squared, pounds per acre, individuals per kilometer, etc.
Processes are the interaction, or transfer of material between components.
This takes place when any kind of transfer occurs. For instance, when water flows downstream from a lake to a field, water is being transferred between components, say, from roots to leaves of plants. To keep track of these kinds of processes, scientists measure the transfer of matter in terms of time and yield. Phrases like grams per meter squared per month, or pounds per acre per year refer to these transfers. Driving variables are elements that influence a system directly, but are not classified as residing within the system.