Slab

Slabs are only half the height of their original block, allowing each block to have double the horizontal usage. They also only sell for half of the sell price of the original block.

There is also a version of the null block which is labeled as a wooden or stone slab.

Armor Stand

 * When making farms, sometimes people use slabs as walls to make it look nicer. They also use them to make sure they don't fall into the water next to the farm.