There is no one way to make a cake....some are sweeter than others some have more butter...some use oil....some have no eggs some have lots of eggs...some use baking soda, some baking powder and some only eggs to raise the batter.
Don't be confused....just make a recipe from a tried and true source and enjoy.
eventually you will learn what all the variations mean to the finished product.
Linda C

I agree, cakes are very different from one another. I like the Hot Milk Cake because it is not very sweet and it's relatively dense and moist. My kids don't like it, they like a sweeter and fluffier cake (like the stuff from a box, the heathens!).

AS Lindac says, use a tried and true recipe and then keep track of which ones YOU like. Even something like carrot cake will have a dozen tried and true recipes because we all like something different. I like mine loaded with pineapple, raisins, coconut. Others are purists and only like carrots. You gotta find the recipes you like, and then you're all set.

Annie

Cakes (or cupcakes) that use oil instead of butter always have more sugar, to compensate for the less-good taste of the oil. You can often reduce the amount a little.

As to baking powder and baking soda, there are many, many poorly balanced recipes out there. The buttermilk vs. plain milk has to do with the difference in these leaveners. If the cake is leavened with soda, there must be an acidic ingredient to react with it, or there will be no reaction that produces carbon dioxide and leavens the bread. Buttermilk is a common acidic ingredient that accomplishes this. One quarter-teaspoon of baking soda is enough to raise one cup of flour. Many recipes have far too much. You can reduce it. Baking powder already contains both the alkaline and the acidic components, so plain milk is fine. About 1 1/4 tsp of baking powder is needed for each cup of flour.