Stupid ? about HardDr backup

How do I know if my stuff is in the harddrive back up ??

How do I get it out ?

The computer wants to back up everything every hour I cured the "everything" part, haven't found a way to change the timing other than turn off 'Time Machine'.

This external harddrive is powered by the computer. When I unplugged it, it said "improper device removal blah blah" Has anyone's files actually been corrupted by 'improper device removal' ?

I have a fairly new Mac.

Thanks for helping a dummy

We use Time Machine too. iI've never had data corrupted bt removing the device but I do TRY to remember to do it properly.

As for the backup, it only backs up the changes. It is NOT intuitive in appearance but it does work because the lovely Mrs_B had a H.D. Failure and cried when the Apple tech told her that the drive, and all the data, was toast . . . And then, like Superman, I saved the day by saying we had a Time Machine back-up! When the computer came back from repair I simply restored it from the Time Machine and it has worked ever since.

If you have data on your computer that is valuable to you, I would definitely recommend off site backup. I have mine backed up on my It guys computer in addition to an old computer that is set up as a backup computer.
There are several commercial backup sites. The cost is low, and is worth it, even for personal use.