Paypal refund option - how does it work?

I heard that if you sell something, after your payment has been sent, the buyer can cancel the payment and paypal will refund him(with the money from your account).

Can't I get scammed by selling a domain name and then after a period of time the buyer would ask for a refund? I would lose both the money and the domain...

I heard about lots of people using AlertPay that have their accounts on negative( like minus 100$) balance because their buyers asked for refunds and I think PayPal uses the same system as AlertPay.

So how can I be sure that after I receive the money on PayPal, they are MY money forever and they can't be taken back by the buyer?

 

paypal just sucks!!! nothing else

 

Paypal usually does chargeback.Well,after 180 days you get the money,then no chargeback .

 

Buyers can't click REfund button, there are any. But chargebacks occure quite often, especially with stolen paypal accounts and credit cards

 

So how does this chargeback work on PayPal?
If I sell you a domain today, you can in the first 180 days, to ask for a chargeback? That means Paypal would deduct the price for the domain from my account ? Wouldn't that leave me without money AND the domain?