a subdomain is basically an extension of another domain. like oatmeal.tvirtas.com; tvirtas.com is the domain and oatmeal is the subdomain. you can use a subdomain from us to do anything you would do with a domain, without having to buy the latter. it's like the subdomain is a subspace and the domain is a suitcase... contact us to request a subdomain. to make it easier to read through, you could write your email as something like this (not required, but encouraged): "i would like the subdomain (your choice here) on tvirtas.com. i'd use this subdomain for (your reason here), and i would want it pointed to (your records here). i swear in good faith that i will not use this subdomain for malicious or illegal purposes."