External hard drive!

In_for_a_Bargain

Hi have just bought an external hard drive 160 GB & would like some advice before I install it?
1) I realise what backup is but will it do it automatically or will I need to choose what I want?
2) Once everything is on can I then delete photos etc from my computer. I would imagine the answer to this is yes as otherwise it will not free up any space on my computer which I thought was partly the idea?
3) When they are all sorted with information do they remain plugged into computer, if so is that a bit daft as if anything happens to computer won't it happen to the hard drive too?
Sorry to seem a bit thick but don't want to take any chances.
Thanks in advance.

Tallymanjohn

1) you have to either manually copy files over yourself or use a program like Microsoft backup to do it for you - you then get the option to backup everything (a bit pointless) or just your data files.
2) You can delete them but the idea of a backup is in case the originals are damaged. If you delete them you still only have the backup & external drives can fail as well. Personally I would backup pictures to DVD/CD as well before deletion if you need the space.
3) Yes, the idea of external backup drives is that they are kept elsewhere for safekeeping, unless you are just using the drive as extra storage in which case keeping them attached is more usual & does no harm.