There are all sorts of ways of classifying people. The Jungian way of defining people as introverts or extroverts, thinkers or feelers etc. is explained in Talking your Way to the Top.
There is also the Freudian concept of oral, anal and genital personality types. Recently Terence Watts has written a text called Warriors, Settlers and Nomads which traces personality types back to very early human history.
The mode of therapy called Core Energetics uses what it terms character structures. These are very involved descriptions of types including their physiology, traumas suffered, presenting issues. For further information read Core Energetics by Pierrakos or Hands of Light: a guide to healing through the human energy field by Barbara Brennan.
Some people love personality typing, others hate it. We suggest you read through some of the ideas and see how they fit with you. The most important thing is, if using them at all, to not make presumptions about people, or to label them.