What does isolation actually mean?

Just about every time I see the word transformer I see the work "electrical
isolation" but I really have no idea what it means. Obviously there are is
no direct electrical connection but whats the big deal with this? Why is it
important to isolate the mains, say, with an isolation transformer when it
decreases efficiency?

I just don't see the point of isolating something just to isolate it.. there
has to be a very good reason but no one seems to mention it. Like one could
use AC to power a motor that powers another motor that generates AC and
hence there is an electrical isolation... but what good is it?

Thanks,
AD


.

Relevant Pages

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