Wow thanks everyone!! That certainly answers my questions.
"Layers" were mentioned here. That made me think of a follow-up question, regarding layers.
I'll be working on a project where there will be lots of different additions to each page of artwork... text in different places, little drawings etc. All on top of a background which is a photo.
So, I was thinking that it would be good for me to use layers, as every individual aspect of the art can be moved, worked on, or deleted entirely, without affecting the rest of the picture, as long as each part has its own layer.
So, my questions are
1. Am I correct in my understanding of what layers do?
2. Is there any disadvantage at all (besides possibly file size, which I don't care about) to using layers?
Thanks!!