This document discusses key concepts in defining and segmenting target markets. It begins by explaining the importance of understanding customer demographics, geographic locations, psychographics, and behaviors in order to tailor marketing and sales efforts. Next, it discusses segmenting the overall market into narrower groups with specific, measurable characteristics that are large enough and reachable. Examples are provided to illustrate segmenting a broad unemployed market into recent college graduates and professionals in transition. The key takeaway is that narrowly defining the target market allows businesses to create highly focused marketing campaigns that directly meet customer needs.