Interest

 Income is paid on any kind of debit as compensation for loaning the investor's principal to the borrower. Fixed-income securities, such as  bonds. The rates for demand deposit accounts usually fluctuate, according to changes in rate of interest while the rates for bonds, CDs, and fixed contract usually stay constant until maturity.

Dividends

A form of cash compensation for equity investors. They represent the portion of company earning that are passed  on either a monthly or quarterly basis. In general dividends while enterprises usually retain their cash for future growth.

Capital Gains

It represent the  price of a security or investment from the time that it was purchased.  Of course, the markets move in two directions, and any security or investment capable of posting a gain can also result in a loss. Equities rise and fall with the overall markets as well as from corporate performance.

Different types of investments post different types of returns. Some pay income in the form of interest or dividends, while others offer the potential for capital gains. All of these factors together comprise the total return of an investment.