You buy the account, and you can divide up the disk space and data transfer however you like.
You can host an unlimited amount of domains, meaning that you can have as many clients as you'd like as long as they fit in the space and transfer allotments. You don't actually get any free domains.
You can host an unlimited amount of domains, meaning that you can have as many clients as you'd like as long as they fit in the space and transfer allotments. You don't actually get any free domains.