Market segmentation is the process of dividing a total market into distinct subgroups of customers with common needs and characteristics in order to design tailored marketing mixes. It involves breaking the market down into segments based on variables like demographics, psychographics, behaviors, and geography. The key benefits of market segmentation include identifying new product opportunities, designing effective marketing programs for homogeneous groups, expanding the market, improving resource allocation, and enabling innovation. Companies can engage in mass, segment, or niche marketing depending on how broadly or narrowly they define their target segments.