How do (real world) shops accept bitcoin? I thought that it takes some time for a transaction to be confirmed by the blockchain. Even if it is a matter of minut

How do (real world) shops accept bitcoin? I thought that it takes some time for a transaction to be confirmed by the blockchain. Even if it is a matter of minutes, you can't expect customers to wait by the checkout until their payment is cleared. And yet without this confirmation, you are opening yourself up to fraud.