I'm monitoring a particular domain and today I noticed a change in the status. Before it was 'Registrar-Hold' but now it's 'RedemptionPeriod'.

What do those terms mean exactly? Thanks.

Whats the extension?

The following is generally the rule for .com & .net domains:

http://www.snapnames.com/deleteprocess.html

A good tool for estimating the release date is the status checker at FreeWho.com: http://freewho.com/checker/index.php