Taxable wages are the total wages paid to an employee during a specific reporting period, including wages subject to UI, ETT, and SDI taxes. Exempt wages, on the other hand, are wages not subject to these taxes. For example, wages paid to employees under the age of 18 or to certain types of farm laborers are exempt from UI and SDI taxes. Wages paid to employees covered under a bona-fide apprenticeship program or to certain types of disabled workers may be exempt from ETT taxes.