An example of a capital gain is to sell shares of stock for $10,000 for which you originally paid $2,000 - an $8,000 capital gain.
capital gain - Investment & Finance Definition
The income derived from selling an investment for an amount of money greater than its purchase price. To be considered a capital gain, and not an ordinary gain, the investment must have been held for one year or longer. Capital gains are taxed at a lower rate than ordinary income is taxed at. Capital gains can be offset by capital losses in order to reduce the amount of the taxpayer’s overall bill.