In order to accrue interest, you deposit funds into interest-bearing investments. These items include CDs, bonds, savings accounts, and money market accounts.
Dividend income refers to the distribution of earnings from companies to their shareholders from stocks or mutual funds. This income is taxed, but it depends where you have this money, like in a retirement account or IRA.
Investing in real estate is a highly popular way many millionaires have built — and continue to — build wealth from. Many times it can be from flipping properties or holding on to property for years until the value goes up.
Another investment income type is through capital gains. A capital gain happens when there is an increase in value of an asset and that asset becomes worth more than the original purchase price.