"so the way I understand this, is when I go into the original master, make my changes aperture will have my original master and the changes made to that image...."
Yes. The master file contains the actual pixels, and the version changes (increase red and green signal 10 points, increase shadow levels 12 points, etc.) are saved in a separate file. When you export a version it applies the changes to the original file and creates a new file. Each version is a separate file of changes to the original pixels.
"so the way I understand this, is when I go into the original master, make my changes aperture will have my original master and the changes made to that image...."
You can create a new version from the master or you can duplicate a version to continue to make more changes based on that duplicated version. For example, if I apply adjustments to the levels of the original master, I will now have the master and one version. I can continue to make changes to that first version or I can make a duplicate of it, apply the monochrome mixer to the duplicate and have two versions, one with just the levels and the other with the levels and monochrome adjustments.
"My other confusion is say, I tweak an image, come back 2 weeks later, go and print the image, and find I need to add some magenta to my image....will I get a new file version or will it replace that data to the same file that I originally tweaked....or will it create a new file version with those changes."
If you tell Aperture to create a new version with each change it will, otherwise it will update the current version. You can do it manually or by setting a preference to create new versions automatically.
Hope this helps.
Jim
