Both will be for live sites.
I have two purchases of PowerCMS2 under this (neilo) account, and I was given a serial number for each of them.
Over the weekend I bought two new copies under my other (neil393381) account (Order # 65U888114L9877320) as I thought that I should benefit from the special offer (50% off) and have a couple of copies spare for future use.
When the order completed ($99.98) I had PowerCMS2 added to my downloads, but only one serial number in this case, hence my query.
PowerCMS 2 v2.1.0 (2 at $49.99): $99.98
Serial # xxxxxx-xxxxx-xxxxx-xxxxx