Sponge Cake vs (UK) Angel Cake: what's the difference Having made various random cakes over the years, I'm trying to get my head around what I'm actually doing, so I can experiment a little I suppose.

Now, a pound cake is butter+sugar, then eggs, then flour (in 1:1:1:1-ish usually), and so's a (UK) angel cake (but in a different ratio). In saying that, there's lots of important details I've missed out that very with each individual recipe. But what are the important differences, the ones which differentiate angel from pound, in terms of taste and category? 

I notice that angel cake recipes have much more "flour" in proportion to the other ingredients? Is that the thing that can be best said to separate them? 

Also they tend to have baking powder (in addition to s.r. flour)? Is that important, or just a co-incidence?

Every recipe differs in tiny little ways from all the others that it's hard to see the pattern.

I'm happy to make a bad cake or two while mucking around, but some sage advice would be welcome as to the general lie of the land as to the essential differences between the cake types.

I'm an analytical type so any framework will help me mess around in the kitchen even though I realise that such things are very much in the eye of the beholder, and other people may not use the same names.
Simply the diference between is that the angel food cake has a lot of egg white, along with flour,sugar,salt, and vainilla, and optional also lemon peel and other ingredient. and its characterized because of the white color, non fat, and non chemical leaveners, which makes it a very "light" cake. By the other hand the sponge cake contains chemical leaveners that might not ve needed to use chemical leaveners, because you can use beaten eggs whites along with beaten yolks instead or use both as well, i recomend you use both for a really nice spongy results. And contains fat such like butter, margarine, or oil. And there the whole eggs are mixed together with sugar, or separated eggs to form a meringue and then beat the yolks with the other half of sugar and combine these with the dry ingredients with the folding method to avoid loss of air as posible to get as result a very spongy cake. or just beat the whole eggs with sugar, then the fat, liquid ingredients and then dry ingredients, for a more dense and less delicate to do and less fluffy cake. imo it doesnt take so palatable or tasty to me the light cake rather than the greasy,and flavory spongy cake.