Minecraft schematics are files that contain a cube of blocks that can be loaded into your world–usually the overworld. This cube of blocks is usually a structure.
Merlin’s Forge comes with a file of over 200 schematics ready made.
You can add your own schematics to this file using the Schematic Stick and the command /sch save <file name>.
Schematics are loaded using the command /sch load <file name> after a Building Block has been placed. At least on GOLD INGOT must be in your inventory to cover the cost of the schematic.
If you are unhappy with the schematic or the placement of the schematic, you can restore the original blocks with the command /sch undo.
Click here for more detailed information about using schematics in Merlin’s Forge.