Alcohol comes from yeast.
1. you create sugar water.
this involves making lots of hot water (but not quite boiling hot), and then cooking grains (malted barely) in it. This gets the carbohydrate out of the grain and into the water.
2. you put in hops for flavoring (that shitty bitter taste)
3. you put yeast into the sugar water
The yeast poops out alcohol and farts out carbon dioxide. Too much yeast results in too much alcohol too quickly and then the yeast can't make more alcohol cuz they're swimming in their own poop. When the yeast is done making alcohol, they clump together and fall to the bottom, leaving the rest of the liquid clear. That clumping thing is called flocculation.
If you create the sugar water from grapes, and let the yeast do its work in an OPEN container (so that no carbonation occurs) you get wine. If you distill wine (boil it so that the alcohol evaporates first, and you collect all the alcohol) you get brandy.
The carbonation comes in two ways:
All beer leaves the brewer carbonated. This is accomplished in one of two ways - natural and forced carbonation. In both cases beer and carbon dioxide are sealed in a container under pressure. The beer absorbs the CO2 giving the beer its fizz.
Natural carbonation results from the fermentation process. Fermentation produces alcohol and carbon dioxide as yeast digests the sugar in the wort. Although most of the carbon dioxide is allowed to escape during fermentation the brewer will seal the beer in a container when it is almost complete. This is how natural carbonation is used to carbonate beer in holding vessels at the brewery and in casks.
Anther way to use natural carbonation is in the bottle. In this case the beer is allowed to ferment completely. It is left unfiltered which leaves active yeast suspended in it. Then a small amount of sugar is added at bottling time. Once the bottles are sealed and the yeast begins to act on the sugar, CO2 is released and absorbed by the beer.
When beer is force carbonated it is allowed to fully ferment. Then CO2 to pumped into a sealed container with the beer and absorbed into the liquid.