A Dividend is a portion of the company's earnings that it pays to certain a certain class of shareholder, because they own the shares of that company. This is usually paid out yearly, usually as cash. Companies that are profitable usually pay out Dividends.
The Dividend rate (DIVIDEND_RATE) is the percentage of stock price that the company pays as Dividend. For instance, at the end of the year, if AAPL stock price is, say, $100 and Dividend rate is 0.88%, then AAPL will pay (0.88 / 100 * $100) = $0.88 per share to some of its shareholders.
Dividend yield (DIVIDEND_YIELD) is the Dividend divided by the price of the stock at that time of the year. Dividend yield is almost the same as Dividend rate, except Dividend yield is a ratio while Dividend rate is a percentage. Example: MSFT paid a Dividend yield of 0.0084 in 2020, which was a Dividend of $0.56 per share.
Five Years Average Dividend Yield
FIVE_YEAR_AVG_DIVIDEND_YIELD is the the mean Dividend yield of the past 5 years. Example: AAPL has a five years average Dividend yield of 1.34%, which was calculated by taking the Dividend yields of the past 5 years and then summed and divided by 5.
Trailing Annual Dividend Rate / Yield
The TRAILING_ANNUAL_DIVIDEND_RATE or TRAILING_ANNUAL_DIVIDEND_YIELD is the total Dividend paid over the past 12 months to the shareholders, as a percentage of the stock price. For example, in 2020, AAPL has a trailing annual Dividend rate of 0.82%.