This document provides an overview of demand and supply basics. It defines demand as people's want or need for a good or service backed by their ability and willingness to pay. It explains how to draw a demand curve by plotting a demand schedule that shows quantity demanded at different price points. The key features of a demand curve are that it slopes downward, showing an inverse relationship between price and quantity demanded due to diminishing marginal utility. Movement along the curve represents a price effect, while a shift in the curve can occur due to non-price factors like changes in income, substitute prices, or expectations. The document uses the example of water demand in Kathmandu to illustrate these concepts.