From Longman Business Dictionary
focusfo·cus /ˈfəʊkəsˈfoʊ-/ noun [uncountableU]MARKETING when a company tries to serve particular groups of customers in a market with particular needs, rather than trying to serve the whole market —focuser noun [countableC]The focuser seeks to achieve a competitive advantage in its target segments even though it does not possess a competitive advantage overall.