periodic system of inventory refers to a method of inventory management where updates to inventory levels are made at periodic intervals, rather than continuously. This system involves counting and recording stock levels at regular intervals, such as weekly, monthly, or quarterly. While the periodic system is often used by smaller businesses or those with less frequent inventory turnover, it may not provide the real-time data that more sophisticated systems offer. For businesses with high transaction volumes, the periodic system may be less efficient compared to a perpetual inventory system that updates inventory levels automatically with each transaction.