What does the ex-dividend date mean?

How can you trade stocks so you buy it in time to obtain the dividend, but make money and sell it too? Or are dividend stocks better to hold and get income? What are some good stocks to buy?

I’m looking for a link to such studies here, so hopefully I can save time from doing my own studies. Basically, I’m looking for edges in the market, and even if dividend stocks grow at the same rate as non-dividend stocks, and dividends are a percent, than I will have a percent plus compounding on that percent every year. May not be much, but every edge counts. Please note that only statistics and studies will help me here. Thanks!

AT&T is decades old but it’s history seems to be to do worse than the stock market.

I am interested in knowing one or more stocks that have traditionally beaten the market, especially if they are dividend stocks.