What is a bargaining unit?

"Bargaining unit" refers to a group of employees sharing mutual interests within a given employer unit, comprised of all or less than all of the entire body of employees in the employer unit or any specific occupational or geographical grouping within such employer unit. (Book V of the Labor Code of the Philippines)

According to Rothenberg, a proper bargaining unit maybe said to be a group of employees of a given employer, comprised of all or less than all of the entire body of employees, which the collective interests of all the employees, consistent with equity to the employer, indicate to be best suited to serve reciprocal rights and duties of the parties under the collective bargaining provisions of the law. (Rothenberg in Labor Relations, p. 482, cited in G.R. No. 77395).