Basics !?!

Ive been buring back up copies of PSX games for time now but ive just got hold of a Dreamcast. The thing is I would like to make back-ups but i think i know that you cant just copy the disks you have to make them with ISO's and things. So could someone please tell me wot an ISO is? I have an idea but not too sure.

I have all the software needed, Fireburner, Diskjugler, IsoBuster etc but dont know wot to do with them.


Any help will be help, so if you think you could help me please give me a helping hand. Thanks.