Consumer equilibrium refers to the point at which a consumer maximizes their satisfaction or utility based on their limited budget. It can be explained using two approaches - the indifference curve approach and the marginal utility approach.

1. Indifference Curve Approach:
The indifference curve approach is based on the concept of indifference curves, which represent different combinations of two goods that provide the same level of satisfaction to a consumer. Here's how consumer equilibrium is explained using this approach:

- Indifference Curve: An indifference curve is a graphical representation of different combinations of two goods that give the consumer the same level of satisfaction or utility. The consumer is indifferent between any point on the curve because they derive the same level of satisfaction from each combination.
- Marginal Rate of Substitution (MRS): The MRS is the rate at which a consumer is willing to exchange one good for another while maintaining the same level of satisfaction. It is measured by the slope of the indifference curve.
- Budget Constraint: The consumer's budget constraint represents the various combinations of goods the consumer can afford given their limited income and the prices of the goods.
- Consumer Equilibrium: Consumer equilibrium occurs when the consumer chooses the combination of goods that maximizes their satisfaction, subject to their budget constraint. This happens at the point where the indifference curve is tangent to the budget constraint.
- Tangency Condition: The tangency condition states that the slope of the indifference curve (MRS) must be equal to the slope of the budget constraint (price ratio of the goods). This ensures that the consumer is maximizing their satisfaction while utilizing their entire budget.

2. Marginal Utility Approach:
The marginal utility approach focuses on the concept of marginal utility, which is the additional utility or satisfaction a consumer derives from consuming one more unit of a good. Here's how consumer equilibrium is explained using this approach:

- Law of Diminishing Marginal Utility: According to this law, as a consumer consumes more units of a good, the marginal utility derived from each additional unit decreases.
- Consumer Equilibrium: In order to maximize their satisfaction, a consumer will allocate their budget in such a way that the marginal utility per dollar spent is equal for all goods. This means that the consumer will allocate their budget in a way that the marginal utility derived from the last dollar spent on each good is the same.
- Marginal Utility Analysis: By comparing the marginal utilities and prices of different goods, the consumer can determine the optimal combination of goods that maximizes their satisfaction. The consumer will continue reallocating their budget until the marginal utility per dollar spent is equal for all goods, achieving consumer equilibrium.

In both approaches, the consumer equilibrium is achieved when the consumer is maximizing their satisfaction or utility given their budget constraint. The indifference curve approach focuses on the consumer's preferences and the trade-offs they are willing to make, while the marginal utility approach emphasizes the diminishing marginal utility and the allocation of the consumer's budget.