Microeconomics is a branch of economics that focuses on the behavior and decision-making processes of individual units within an economy, such as households, firms, and consumers. It studies how these entities interact in markets to allocate resources and goods, how prices are determined, and how individual choices impact supply and demand.

Key concepts in microeconomics include:

1. Supply and Demand: Examines how the quantity of goods and services supplied by producers and the quantity demanded by consumers interact to determine market prices.
2. Elasticity: Measures the responsiveness of supply or demand to changes in prices, income, or other factors.
3. Opportunity Cost: Represents the value of the next best alternative that is foregone when a choice is made.
4. Marginal Analysis: Analyzes the additional benefits and costs of a decision to determine the optimal choice (e.g., producing or consuming one more unit of a good).
5. Market Structures: Studies how different types of markets operate, including perfect competition, monopolies, oligopolies, and monopolistic competition.
6. Consumer Behavior: Focuses on how individuals make decisions to maximize their utility or satisfaction from goods and services given their budget constraints.
7. Production and Costs: Looks at how firms decide on the optimal combination of resources to minimize costs and maximize profits.

Microeconomics is essential for understanding how individual choices contribute to broader economic outcomes and how policies affect these decisions.