This document discusses segmentation, targeting, and positioning in marketing. It defines segmentation as dividing the market into groups with distinct needs, and discusses different bases for segmentation including geographic, demographic, psychographic, and behavioral factors. It also outlines levels of segmentation from mass to niche marketing. Targeting involves selecting attractive market segments to focus on, while positioning is about creating the right perception of a product in the minds of consumers relative to competitors. Effective segmentation requires segments to be measurable, accessible, substantial, and differentially responsive to marketing strategies.