Canon SX40 night (low light) scenes

[rurulan]

Hello everybody, I'm new to photography and have some simple questions:

1.I've just bought this camera and learning all its features. What would be the difference between these to modes:
"Handled NightScene" and "Low Light"?

2. Second question is more general - since the camera has "Auto" mode why should I use some other settings - like "Beah", "Snow", "Low Light"?
If the camera is set to Auto will this mode select proper settings to shot on a beach, snow, low light?

Thanks,
r.