You have money in paypal funds which you can transfer into your checking account. In our case, we have a paypal mastercard (or maybe visa, I forget) debit card. I get 1.5% cash back when I use it as a credit card (ie, no PIN) so I usually do that instead. With the Paypal card I can also withdraw cash at an ATM, but there is a fee for that so I rarely do that.
We sell on ebay, and we have a website that accepts payment through paypal. I also use paypal funds to "click & ship" through USPS, so shipping charges get deducted that way.