What is Altman Z-score? What is Piotroski F-Score?

Have a query about new terms uses in stock markets? Looking out for information online? Find suggestions from experts on this page.

I have minimum understanding of various ratios used to evaluate stocks. I know what is ROE. I understand EPS, P-E, Dividend Yield, D-E and other well-known ratios. But recently I have heard two new terms, viz., Altman Z-score and Piotroski F-Score. These two criteria are also used to judge the suitability of stocks by the experts and mutual fund managers. However, I have not understood these two terms very well.

I request the ISC experts to kindly explain these two terms.