Group of organization has its own business processes, strategy and policies compared to individual organization. Often they are similar to their daughter organizations yet they needs to be distinguished during your term project.

More often than not you will work with a particular department because of the scope of your project. And you will need to determine the parent of the department.

Reference
http://en.wikipedia.org/wiki/Corporate_group
http://en.wikipedia.org/wiki/Concern_(business)
http://en.wikipedia.org/wiki/Parent_company