Attrition and turnover are two sides of one very bent and misshapen coin. Both deal with the loss of employees; however, they find their difference in the end result.
Attrition is a diminishing of strength or effectiveness of manpower or something else through an attack or pressure.
Regarding businesses, attrition occurs when an employee leaves the company and no actions are made to replace them, so eventually, the position is eliminated, and the company has grown smaller. This could also refer to a loss of resources or goods wherein no action was taken to protect or replace them.
Turnover is the rate at which the employer replaces employees who have left the company for any reason. Failure to fill these vacant positions feeds the insatiable hunger for attrition.