The overworld is a guaranteed for life map (no map resets!) where players builds will always be safe.
PvP is not permitted without agreement (or in marked areas) and griefing is not allowed per the rules.
The map streches from 30k to -30k in each direction with plenty of undiscovered secrets.
The Nether is the anarchy zone of Crazy-Fools.co.uk where PvP and griefing is permitted. Don't trust anyone who tries to lure you into the Nether!
Since the Nether is technically a wasteland, it is subject to chunk aging. If a chunk reaches 12 months without being accessed it may be regenerated.
The End is an alternative zone where currently no PvP or griefing is permitted.
Re-released in 2021, Winter World is a waste land where snow builds up across the lands. Make sure you equip leather armour to keep warm and stay away from the dive bombing explosive phantoms!
If you wish to visit Winter World, grab some fresh rabbit meat and find the emerald portal. Not sure where it is? Ask around, theres likely a warp!
It was recently decided that PvP without agreement and griefing are not permitted in Winter World.
Water world was a world full of .. water. Small islands popped above the surface and boats could be found in the vast oceans.
Sky lands was a hidden world generation type in Minecraft before the end existed. It consisted of skyblock like lands. Sky lands was removed from vanilla Minecraft once the end was introduced.