CDs are a retro way to listen to music, and just like every other confusing acronym on the planet, they're also a way to earn more money—and save faster.

The less dance-happy type of CD stands for Certificate of Deposit. They're a little like savings accounts: you put your money in and earn interest. The difference? With a CD, you're promising the bank that you'll keep the money in the account for some set amount of time (which can be months or years, depending on the CD).

Because you're promising that bank that you won't come running for your money, they know exactly how long they have to loan it out…or put it into a pool and swim in it. For that reason, you'll get a higher interest rate because it's less hassle for the bank.

Let's do a quick pro/con list:

Pros:

• Higher interest rates (usually 3-9% depending on how long the term is).
• Helps teach you delayed gratification.

Cons:

• You can't take your money out whenever you want.
• If you have an emergency and have to take your money out, there's a big fee, which will cancel out the high interest rate—and then some.

And that's about it.

If you decide a CD is the way to go, keep your eye out for ones that are made especially for the under-21 crowd; they come with perks that will be specifically helpful for your not-yet-rich demographic.