The term "turnover rate" is commonly used in the business world to refer to the number of employees who leave a company within a certain period of time, typically a year. However, there are various other terms that can be used as synonyms for this concept, such as attrition rate, churn rate, and retention rate. Attrition rate typically refers to the natural reduction of employees due to retirement, resignation, or termination, while churn rate is commonly used in industries such as telecommunications to refer to the rate at which customers cancel or switch services. Alternatively, retention rate refers to the percentage of a company's workforce that remains employed over a specific period, and is often used as a measure of employee satisfaction and engagement.