Define "Members of" field in Account

[Neutgens]

Community Edition:

Could someone please help me understand the "Members of" field in the Create Accounts window?

First, I don't understand what this is used for. The help says:
Member of. Enter the names of organization associated with the account.

Which doesn't make sense to me.

Also, there are two buttons next to this field: Select and Clear. But when I hit select, I just get a search window, which again doesn't make sense to me. Since I'm just getting started, there is nothing to search for.

Any help would be appreciated.

[andopes]

It means a subsidiary company.

Cheers