Explain more about stocks on iphone?

I want to know what it is. I know most about it. The part that is getting me is the market cap. When I select it it shows 398.9B and I need to know what the (B) stands for? Also give me as much as other info on how to read and understand stocks on iPhone a little better.

The B stands for Billion. The company that you are looking at is valued at $398, 900, 000, 000 at the current market price. It is arrived at by multiplying the number of shares outstanding (float) x the current stock price.

Other common quote data: Open - the opening price on the current day. High: High price for the day Low: Low price for the day Volume: Number of shares traded since opening EPS: Earnings per share. P/E Earnings Per Share divided by the stock price. (Normally the P/E is based on the prior day close and the current 4 quarters of earnings)