Hi, i currently have my Time Machine to backup to an external hard drive... i have a few questions which i hope someone can help me with:

01 - i see that there are several versioned backups on my external drive... when i open the actual Time Machine app, it allows me to scroll through versions... am i right in saying these are the versions on the mac itself and not the external hard drive...
a - what versions are copied over to the external hard drive OR what is the difference between what you see in the Time Machine app and the actual files on the external drive
b - can i go into the Time Machine, in a specific folder and go back 3 hours and retrieve a file that is now deleted and copy it... if so do i just CMD + C and then come out of Time Machine and past the file on my desktop

02 - is it possible to have 2 backups... as in backup the same mac multiple times onto multiple external hard drives

03 - is it possible to revert your whole system back to a certain date (let's say 2 days ago) and then shut down your computer and the next time you start it, it would be as if you were turning it on from 2 days ago... if so how is this done, thanks in advance for your help