LOD is general short for “Level of Detail”.
First of all, mesh of your terrain should look like:
generally see how @remy_vd was doing one.
(on videos he limited to 30 fps as i see, bit it would be much more)
About a LOD, i was unable to find video, but i seen someone doing voxel LOD presentation video.
LOD should replace far terrain with lower detail mesh to optimize.
something like(for normal terrain here - not voxel)
