Always here to reply your questions so no worries 
All TerraUnity products operate on Unity’s built-in terrain system, so no custom terrain system or shaders are used in TerraLand. However, we are going to release a new product called “TerraEnhancer” soon which includes custom advanced terrain shaders & content to achieve the best looking photo-realistic terrains in terms of shape & graphics.
In TerraLand, terrain texturing is in the standard way using splatmaps where each splatmap can hold up to 4 images’ position data in the terrain data asset. Following is a picture of a terrain data that has 16 textures on it:
You can see the images are tiled in 4 splatmaps following the R,G,B,A channels to finally create a tile of 4×4 (16 images) on terrain surface.