Answer:
Corporate bonds are investments made to corporations that function much like certificates of deposit, except that they are not government-insured in any way (like with FDIC).
For example, if you pay $20,000 for a corporate bond for two years, with a 5% APR, then, after two years, they should pay you $22,050.
However, unlike with certificates of deposit, the government won't pay you back just because the corporation can't. They make up for that by offering a higher interest rate than CD's generally do, but they're paying for risk. As such, you should not put all your eggs in one basket; diversify your investments.