I've written that people are patterns, but that kind of thinking is not too useful. The most useful way I have found to conceptualize of people is to think of a person as being defined by a certain set of traits, say intelligence, knowledge, morality or anything else you can think of. Think of each trait as existing on a scale going from - X to +X. These traits together create a set of Axis. 2 traits = a 2 dimensional space. 95 traits = 95 dimensions. A person is a cloud in this space. Why a cloud? Because a point would mean that any change in temperament or character would make them a different person. We see people as being the same as long as their personalities (collection of traits) stays roughly constant. Hence why a cloud is more appropriate than a line.
Eliezer Yudkowsky coined a term for this: "Empirical cluster is personspace", which is a very good concept handle.