From a consumer perspective, I recall from my schoolboy physics that AC suffers from lower transmission losses over distance, and is safer as if your body shorts a DC source, you can go into spasm and hold on to it, whereas AC will repel you.
Also there was something to do with asynchronous devices used for timing not working properly on DC, as they take their timing from the number of cycles per second/Hertz, typically 50 or 60.
As I say, schoolboy physics, I'm sure someone with greater knowledge will correct the above if wrong.