This Act protects certain classes of employees (as defined in section 2 of this Act) by providing minimum terms of service that cannot be contracted out or diluted to the detriment of these employees. Whilst this Act covers the classes of employees referred to above, Part IV of this Act which deals with more basic terms of service such as rest days, shift work, holidays, retrenchment benefits, leave and hours of work only applies to workmen (as defined under this Act) and other employees whose monthly salaries do not exceed S$1,600.