The block time is 2 minutes. You can choose to wait for 0 blocks or 100. The longer you wait the better the security of your transaction, because there's more PoW behind it. All crypto work like this. You also get more security behind your tx by waiting in a PoS system.
If you're buying a coffee the vendor is likely to let you leave the shop after no confirmations (as soon as their node hears about the transaction) but if you're buying a car the same is unlikely to be true.
If you're buying a coffee the vendor is likely to let you leave the shop after no confirmations (as soon as their node hears about the transaction) but if you're buying a car the same is unlikely to be true.