What is better a high or low P/E ratio?

[underexposed...]

ok....P/E ratio is (Price/Share)/(Earnings/share)

if the P/E is low then its share price is low compared to its earnings per share.....this either means that the stock is undervalued or no one cares about this stock for some reason.

if the P/E is high then the share price is clearly not based on its current earnings. IF the stock is a newly introduced to the market then the investing public has high anticipation of further earnings ....either through their existing product that is ground breaking or the stock is pumped by the media leading expectations (Facebook was like that initially)....Hi-teck stocks are like that, oil companies or mining companies can get like that if they tout the potential of a new find, bio-research is like this too

Beware of extremely high P/E numbers....often these expectations are based on nothing more than dreams...not reality. Similarly beware of extremely low P/E numbers....there is a reason why the investing public is ignoring this stock.

When you compare P/E ratios do so within the same industry/sector. It is silly to compare a stock in two separate groupings

Google Inc. [GOOG](Technology/Internet Information Providers) with a P/E32.13
is actually pretty low for this industry/sector

American Woodmark Corp.[AMWD]Consumer Goods/Home Furnishings & Fixtureswith a P/E of 31.01 is actually quite high for this sector

they are not equivalent comparisons...if you are interested in a particular stock and you want to compare its P/E do it with like stocks....apples to apples not apples to nails