Petty cash book is a record of small and routine transactions made by an organization using cash. These transactions are usually for small amounts of money, such as office supplies, parking fees, and other miscellaneous expenses. The petty cash book records transactions on both the credit and debit sides, meaning that it records both the inflow and outflow of cash. This helps to accurately track the organization's petty cash balance and ensure that it is being used efficiently. The petty cash book should be balanced at the end of each day or week to ensure that the amount of cash on hand matches the recorded transactions.