Parenting allows one parent to control the children. For instance in rotation, if you parent one layer to another, the child can be made to rotate around the parent instead of rotating around it’s own axis.
Adjustment layers are take all the layers below them and look at them as one layer. So if you have 15 different pictures and you want all of them to be sepia tone, you can create an adjustment layer and put on the CC Toner and make them sepia. And if you decide to change the color, you only have to change the effect on the adjustment layer. If you’d applied that effect to all 15 layers, you would have to make 15 changes, so it’s a big time saver.
I would strongly suggest you start here to get a grasp of the basic fundamentals of AE: Getting started with After Effects (CS4, CS5, CS5.5, & CS6)
Johnny Cuevas, Editor
Thinkck.com
“I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work.”
—THOMAS EDISON on inventing the light bulb.