问个关于hexonet域名商的问题.

trips

看上一个域名.但是还有段时间才到期.
去他们网站看了下.提示
Using our advanced backorder system, we will attempt to register the domain as soon as it becomes available.
Backorder * - If the backorder is successful, you will pay 19.90 USD
Backorder Lite ** - Upon success, and if no other Backorders are placed on this domain, you will pay 9.50 USD
Registration attempts are only executed for active accounts with sufficient funds at the time of domain expiration
(*) Domains with multiple backorders are sent to private auction
(**) Based on first come first served priority in the Backorder Lite category
他下面的2个选项一个付19.9 跟9.5具体是啥子作用?
19.9的是到期立马转移到我帐号还是.
然后9.5的还什么lite...
看不懂看不懂.来个大佬!