Fences

[Omniwar0801]

So im building a palisade and i says i can build a gate there when i try to make one between two conerpost that are 2 spaces apart

and what does the option seal do?

[VileThings]

If you seal a cornerpost you can no longer extend it in any direction - neither can anyone else. It was introduced as protection against griefers who would extend your own palisade to block your gate.