Which of the following best describes inventory turnover?

Inventory turnover refers to the rate at which a business sells its inventory and replaces it within a specific period, typically measured over a year. This measure is crucial for understanding how efficiently a company is managing its stock. A high inventory turnover indicates that a company is selling its products quickly and replacing them frequently, which is often a sign of strong sales performance and good inventory management.

In contrast, the other options describe different inventory-related concepts. The total value of inventory held refers to the monetary worth of all items in stock, which is essential for financial reporting but does not indicate sales performance. The duration products remain unsold in stock describes the time items spend in inventory without being sold, which reflects inefficiency but is not the same as turnover. The percentage of returned items focuses specifically on the returns aspect of sales, rather than how often inventory is sold and replenished, and does not directly assess turnover rates.

Thus, the explanation of inventory turnover as the rate at which products are sold and replaced encapsulates the concept most accurately.