I must have changed some setting because every time I make any change to a photo I now receive the following attached message.
1. Does a Virtual Copy actually make a separate file in my Library?
2. Why is it now prompting me with this option after every change?
3. If I want to choose to make a Virtual Copy, what is the difference between choosing to make the current photo a Proof vs. Create Proof Copy? Is the Proof Copy the Virtual Copy?
Creating a virtual copy for soft proofing allows you to apply the appropriate paper profile to that proof copy so that you can get a fair representation of how the image will print. It is not another copy of the image, but rather a separate set of metadata settings that point to the same image. This allows you to adjust the virtual copy as needed to ensure that you get the print you want.
It's possible that you are seeing this message because you may have reset your preferences recently. You will see that there is a "Don't show again" checkbox that you can select, and this will prevent this message from being seen again in the future. It will still be possible to create a virtual copy for soft proofing, as there is an option underneath the histogram when soft proofing is enabled.