Confirmation

The acknowledgment of transaction validity via a consensus mechanism intended to prevent double spend. Once a transaction has been added to a block and that block has been verified and added to the chain it is said to have 1 confirmation. Multiple confirmations (additional confirmed blocks) indicate an increased likelihood of transaction validity and a reduced likelihood that the transaction can ever be reverted. Different retailers and exchanges have different confirmation requirements before accepting funds but typically fall between 2-6 confirmations.