OT: american vs european 220

In the US, two separate 110 legs are delivered to the house. When we need 220, the magic of constructive interference is applied, and we get 220. The 220 is delivered to the appliance as two separate 110 wires, a neutral wire, and sometimes a separate ground wire for safety. Because of this arrangement, sometimes appliances (I believe, maybe I'm wrong) will pull 110 from one of the legs to power electronics in the appliance. But I think european 220 doesn't work this way. Is one 220 leg delivered to the house? And the electronics work off that 220 leg? Or are two 110 lines delivered and every outlet gets the sum of those two 110 lines? If it's not two separate legs, I'm thinking that it will be impossible to wire an american 220 appliance to work with european 220. Is this right? brian