Dual boot?

[DLBlank]

I have a fue questions about dual booting.

First, Can u switch OSs w/o restarting? Becuse i know if theres more than one OS installed u have to pick at startup.

Second If its anything diffrent than just picking from an os at startup then what do u need to do to dual boot? becides installing another os on a diffrent hdd or partition.

Thanks