Snow blocks are made up of snow and you can use them for decoration and building. They can also be used to make snow golem with pumpkin. To make a Snow Block you just need snowballs from a snowy area.
In order to make a snow block, the basic item you will have to get is snowballs. So first find a snow covered place and then use your shovel to get at least 4 snowballs.
Now you need to go towards the crafting table to craft the snow block. Four snowballs can make one snow block, so open 3*3 crafting grid on the crafting table and add snowballs in four adjacent cells. You will get a snow block. Add this block in your ready to use stock.