It depends on how much your money is and how fast you want to profit from it.
If you want your money to be more secure, you should save your money in a bank; but your profit is low.

If you want to earn more, invest it online; but the security of your money is weak compare to a bank. I'm not saying that online investment is not safe, but it is risky.

If you want in real estate, it depends if the estate you have invested in will be successful or not.

I think, gold is the safest, since gold is more expensive as time goes by.