CBAs often open with a description of the agreement, including the effective dates and purpose. The Washington State CBA describes its purpose matter-of-factly as the specification of wages, hours, and other terms of employment.
A 2008 CBA between Great Atlantic and Pacific Tea Company and Union Local 27 outlined a loftier purpose that included the promotion of "cooperation and harmony" and the recognition of "mutual interest," among other things.
Generally, CBAs exist to bind employers and employees to a set of workplace rules. Most of the document is dedicated to defining those rules. Common topics are wages, overtime, working hours, benefits, rules for work, hiring practices, disciplinary procedures, and seniority. CBAs will also define the high-level responsibilities of the employer and the union and detail the dispute resolution process.