Snow Block

Snow is a full-sized block version of the snow layer.

Obtaining
When broken with a shovel, snow drops snowballs. If mined with a Silk Touch enchanted shovel, it drops a snow block.

Unlike snow layers, snow blocks will not melt from higher levels of light, nor get destroyed by water.

Natural generation
Snow generates naturally in ice plains spikes biomes.

Crafting
Snow is crafted from 4 snowballs, allowing the player to create it through their inventory crafting window.

Snow Golems
Snow is also used to make snow golems by putting 2 snow blocks vertically and a pumpkin on the top as the head. Note that the pumpkin has to be placed last for this to work.

Trivia

 * Snow may still fall on top of snow blocks, making them look taller than they actually are.
 * When a snow block is on grass, the grass block changes to a different "snowy" texture as if a snow layer is on it.
 * However, since snow is a solid block, the grass will change to dirt shortly after.