Compound Interest Question

[nydoc]

Hello all, I'm looking into investing in an account that compounds intrest annually. I was playing around with the rates at http://www.1728.com/compint.htm. Just a quick question, (I'm young). When I open an account, would I have to pay taxes, and is it just a one time deposit that compounds over time or would I have to keep depositing annually. Thank you

[midas]

You only pay taxes on interest you earn for that tax year.

Why would you ever invest in an account the compounds annually - is it a CD?