At each point on an indifference curve, what remains constant?

At each point on an indifference curve, the total utility derived from the consumption of two goods remains constant. An indifference curve represents combinations of two goods that provide the same level of satisfaction or utility to the consumer. Therefore, regardless of the specific combination of goods on the curve, the consumer's total utility does not change; they are indifferent between these combinations because they yield the same level of satisfaction.

Marginal utility, which refers to the additional satisfaction gained from consuming one more unit of a good, can vary along the curve depending on the quantities of the two goods consumed. Average utility, which averages the total utility over the quantity consumed, is not a focus of an indifference curve, as it pertains more to the ratio of total utility and consumption amount, but again does not hold constant at every point. Consumer income does not remain constant along an indifference curve either, as a shift in income would typically result in a shift of the entire budget constraint and potentially change the level of attainable utility.