The account owner is an account admin, but with more rights and permissions. By default, the account owner is the user who created the account. There can only be one owner per account.
At the top of all rights granted to other users, owners can:
View and edit billing information.
See subscription info.
See the list of purchased add-ons and begin trials of new add-ons.
A detailed chart comparing the rights of license types, and what each can and can't do, is available on our User Rights by License Type help page.