This creates a starch inside the grain. The barley can be heated, or kilned, to varying degrees. Then you have the caramel grains where you caramelize the unfermentable sugars. There are still other malts that give you biscuity flavors, toasted malts that give drier flavors. Hops contribute bitterness that balances the sweetness of the malted barley.
Yeasts are of two kinds.
One ferments at the top of the tank at a higher temperature for a shorter time, producing fruity characters. The other ferments at the bottom, but requires a lower temperature and a longer fermentation time. It produces more neutral characters. The two basic styles of beers are ales and lagers. Lager yeast is very delicate yeast.