Work-family border theory “is devoted only to work and family domains. The outcome of interest in this theory is work-family balance, which refers to ‘satisfaction and good functioning at work and at home, with a minimum of role conflict’ (Clark, 2000, p. 751). It also differs from boundary theory in that its definition of borders encompasses not only those psychological categories but also tangible boundaries that divide the times, place and people associated with work versus family.” (Desrochers & Sargent)
According to Clark (2000), work-family border theory “explains how individuals manage and negotiate the work and family spheres and the borders between them in order to attain balance. Central to this theory is the idea that ‘work’ and ‘family’ constitute different domains or spheres which influence each other…Given their contrasting purposes and cultures, work and home can be likened to two different countries where there are differences in language or word use, differences in what constitutes acceptable behavior, and differences in how to accomplish tasks” (p. 750-751). (Desrochers citing Clark)

Boundary/Border Theory and Work-Family Integration, A Sloan Work and Family Encyclopedia Entry. Chestnut Hill, MA: Boston College. As defined by Desrochers citing Clark: Clark, S. C. (2000). Work/family border theory: A new theory of work/family balance. Human Relations, 53(6), 747-770.