As with other cryptocurrencies, the PZM Ledger (Ledger of transactions) is built and stored in a linked series of blocks known as the blockchain. This workbook provides a permanent record of the transactions that have occurred, and it also establishes the order in which the transactions were made. A copy of the Blockchain is stored on each node in the Prizm network, and each account that is not blocked on the node (by providing the private key of this account) has the ability to generate blocks, provided that at least one incoming transaction in the account has been confirmed 1,440 times. Any account that meets these criteria is called an active account. In PZM, each block contains up to 255 transactions, all of which are preceded by a 192-byte Header that contains identifying parameters. Each transaction in a block is represented by a maximum of 160 bytes, and the maximum block size is 32 KB.