There are different ways to study a unit and different names applied in different statistical disciplines.
We may be interested in a unit because we intend to generalize from observations on a few units to a statistical assembly of units. Opinion polling[?] and survey sampling provide well known examples of this type of research.
We may be interested in the dynamics of a unit, how its observable characteristics change from time to time. Economic studies of business firms provide an example of this type of research. (See dynamic model[?].)
We may be interested in the internal functioning of a unit which we can characterize as a statistical assembly. This kind of research often involves interference with the unit such as subjecting it to a treatment or even dissection, in some cases. Field experimentation and clinical trials[?] are examples.
... is land and none of the area is covered with water.
Demographics
As of the census of 2000, there are 17,006 people, 5,316 households, and 4,454 families residing in the ...