Castor sugar / caster sugar

Just that basically...what is caster sugar? I was going to make some cupcakes with the recepie being from a British mag - so not sure if it's a language difference, or I just never heard of it in US?! Oh and while I'm at it - "icing sugar" ?? is that powder/confectioner's sugar??
many thanks!

Caster (also castor) sugar is very finely granulated sugar used in baking. Icing sugar is powdered sugar, i.e. even finer than caster sugar.
Hope that helps!

so i guess my next question then is what's a german equivalent of caster sugar? i have the fine confectioner's kind - i can use that for icing...but caster auf deutsch? thanks so much! (well not that i can buy it today..)

Streuzucker.

I think it's called Feinster Zucker. Found it in Galleria. Not to be confused with Feiner Zucker (normal sugar). It did the job.

Puderzucker is icing sugar (GB)

One could also take normal sugar...grind it in a food processor/blender kind of thing, and you'll have fine sugar (castor sugar). Grind it as fine as you wish.

Be careful with that streuzucker translation. It might be correct, but the Streuzucker I've seen was chunky, like salt for a salt mill/grinder.

I'd take Tom17's suggestion and just grind it. Or be lazy and not even bother. I've never noticed a difference in quality, it just means a bit more mixing before it dissolves properly.

Aye, or just call a friend who has a dandruff problem.
There is no difference in the taste, however, dandruff is ever so slightly coarser in consistency.
Most really good friends would be only delighted to come over to your place and comb their hair over your freshly baked cakes.
Bad luck to "Head & Shoulders"! That gunge is making life very difficult for "Südzucker".

I'm with showem, I just use normal sugar and never notice any problems.