Let's say you have an distributing ETF where the dividend yield of the fund is 2%. This means that at a share price of €100, you receive €2 in dividends each quarter for each share of that distributing ETF that you own. In Belgium, you have to pay a 30% in tax on the dividend, leaving you with €1.40. Depending on your broker, the broker will withhold and declare it for you, or else shift the burden to you. Note that dividends are never guaranteed. Companies can increase and lower them at will, or even remove them entirely.