Sweep Account

You keep a few accounts at the same bank. You have your savings account, your checking account, and a special super-saver account, with the extra-high interest rate.

The checking account is a sweep account. That distinction means that any amount above a certain total automatically gets "swept" into the higher-rate accounts.

So...say you always want a balance of $2,000 in the checking account. You have $1,500 in the account now and deposit $600. The balance should rise to $2,100...but since its a sweep account, the $100 extra (the amount above your $2,000 threshold) automatically transfers to the super-saver account.

It's a way to make sure you're getting the highest possible rate on your savings, as opposed to letting the cash just sit in your checking account.