saving and photo quality

iS IT TRUE THAT SAVING AN IMAGE MULTIPLE TIMES AFTER EDITING IN pHOTOSHOP WILL DECREASE THE QUALITY EVERYTIME YOU SAVE IT?

Well.. depends on what you mean. We're talking the same kind of image file each time right?
If that is the case, then it's a down-right lie that the quality is decreased by each save.

It is the same image only with different enhancements made each time. Such as contrast and/or levels and/or desaturation. I was told this by an instructor years ago, but was never verified. He said that it "made holes" in the data by resaving the image and thus the image quality was lessened by each save. Is this bull?

As Medley clarified it is true if you use an image file such as .jpg(.jpeg). I missunderstood your first question, my mistake. Thought you meant that if you saved an image twice, the second version would be of a lesser quality.
Anyways, Medley solved this already.

(btw, I reccomend saving your iamges as .PNG if you can spare the extra space they take up, no quality loss)