It's a prison server where you mine ores to get money, to rank up. Once you've gotten to the highest rank, you can then rebirth to get special perks and you start the process all over again.
When you rebirth, you lose your balance but no plots, so players mine ores, sell them, buy spawners to make farms, and then they make money fast when they're at a lower rank.
If that makes sense at all :P