The return an investor can make on an equity position is divided into two sections: capital and dividend gain.
Capital gain encompasses the appreciation in the price of the asset, compared to when it was first bought. The difference between those two values is the capital gained by the investor, after selling. This value can be expressed as a percentage by dividing the difference by the initial cost amount.
Some equities pay investors a dividend: a portion of the profits to thank shareholders for owning the asset. This is not mandatory but facilitates a healthy relationship between the company and its shareholders. If an asset pays a dividend, this is included in the return yield. The dividend yield can be calculated as the annual dividend per share divided by the current share price.