Investing is like...
Investing is like gambling
In gambling you usually never know if you will go home the luck winner, or go home with less than you came with. Similarly, When you buy stocks, they can gain allot of value, and go completely bankrupt.
Investining is like saving
When you save money, you want to use it at a later time. Also when you invest, you want to use the money at a later time.
Investing is like a rock
A rock is a sign of security, and when you invest in a retirement account, you will be secure retirement