Market segmentation is the process of dividing a large heterogeneous market into clearly identifiable segments based on characteristics like needs, wants, location, demographics, behaviors, or benefits sought. For effective segmentation, the segments must be identifiable, accessible, measurable, and have unique needs to justify creating tailored marketing strategies for each segment. Marketers commonly segment based on geographic, demographic, psychographic, and behavioral factors like location, age, interests/opinions, usage patterns, and loyalty. The goal is to better understand customers and improve marketing effectiveness.