What is the meaning of "Organizational units" in SAP FI?

1. The elements or structures representing the functions of business is called "organizational units".
2.These are used for reporting purpose across the organization.
3.Examples as follows:
     * Company
     * Company code
     * Business area
     * Consolidated business area
     * Functional area
     * Credit Control Area
     * Functional Management area
     * Profit Centre
     * Segment