Definition for Domain
From Biology Forums Dictionary
1) A defined region of a protein with a distinct structure and function.
2) One of the three major categories of life: Bacteria, Archaea, and Eukarya.
3) In computing, a domain is a network made up of a group of clients and servers under the control of one central security database on a special server called the domain controller.
4) In relation to mathematics, the set of permissible values for the independent variable of a function.