A dividend is where a company decides to distribute some of their profits to shareholders. It is a way for the company to reward their shareholders for investing in the company. Dividends can be either regular (usually declared and paid quarterly), or special (where companies want to pay extra rewards to their shareholders and are usually one-off in nature). A dividend is a zero-sum-game, as it does not affect the overal benefit you get from owning the company. If a dividend of $0.10 is declared, generally the share price will decline by $0.10.
Gotrade shows this information on stock screen as dividend yield; which shows how much a company pays out in dividends each year relative to its stock price. For example, for a stock with a 2% dividend yield, you get $0.02 in dividends every year for every $1 you invest. The dividend yield is based on the total dividends paid by the company in the last 12 months divided by the last close price.