System quotas explanation:
Disk space, MB - Total amount of space allowed for customer, in megabytes.
Bandwidth, MB - Allowed bandwidth, in megabytes.
Domains - Amount of allowed top-level domains.
Sub-Domains - Amount of allowed sub-domains.
ODBC DSNs - Open Database Connectivity Data Source Names limit.
File Manager - Allows you to browse files within your hosting space. Used for IIS as alternative to FTP.
Scheduled Tasks - Amount of scheduled tasks allowed for customer.
Disable Tenant To Create Top-Level Domain - Dissalow your customer to create top-level domains. In other words, customer will not be able to add any domain without asking administrator.