Time Machine Question

hey guys ...i have a macbook pro that I was about to enable time machine on..my question is simple..how exactly does it work considering that the drive will not be connected 90% of the time?

I have a macpro that I have time machine on and I have used time machine editor to do daily backups rather than hourly...I wanted to know ..if on the laptop will it just backup when i plug it in...or do i need to disable time machine when its not plugged in so its not eating up resources attempting to backup?

appreciate the help..

 

honestly i thought it was just overkill - i dont need hourly backups at all..honestly i can probably get away with weekly backups..i also got annoyed at hearing my external every hour spinning...now i have it set to do one daily backup at 3am when im asleep - no worries..have had it running like this for a few months now

 

okay great - thanks