As its name suggests, advanced terrain are more powerful in the creation of terrains.
A hightmap is just a image normally in grayscale colours, which rise up you matrix, modeling therefore your terrain.You can make this image with most paint programs, just making differents shapes in grayscale, an last bluring the image to get something smooth.When you have your terrain ready, you can add all kinda objects you need, houses , animals, trees or whatever you like in you game.
Just search for advanced terraing, and you will find a lot of examples.
cheers.
I'm not a grumpy grandpa