Indifference Curve:  

In microeconomics, an indifference curve is a graph showing combinations of two goods to which an economic agent (such as a consumer or firm) is indifferent, that is, it has no preference for one combination over the other. They are used to analyze the choices of economic agents.

Utility is ordinal and a higher level of utility is better. An indifference curve maps out the relationship between a numbers of consumption packages that maintain an individual's utility (sense of satisfaction) at a constant level. For example, if a consumer was equally satisfied with 1 apple and 4 bananas, 2 apples and 2 bananas, or 5 apples and 1 banana, these combinations would all lie on the same indifference curve.

Indifference curves are typically assumed to have the following features:

• An indifference curve slopes downward from left to right (negative slope). The negative slope is a consequence of the fact that the demand for one commodity (X) increases while the demand for another commodity (Y) decreases (because of diminishing marginal utility of Y), which is necessary to maintain the total satisfaction.
• Indifference curves do not intersect. This is a consequence of the assumption that consumers will always prefer to have more of either good than to have less.
• The curves are convex, which is a consequence of the assumption that as consumers have less and less of one good, they require more of the other good to compensate (corresponding to the law of diminishing marginal utility).
• The Indifference curves are ubiquitous throughout an indifference map. In other words, there exists an indifference curve through any given point on an indifference map.

For a given pair of goods, many indifference curves can be drawn and placed next to each other. This representation is called an Indifference Map. The rational consumer is expected to prefer the higher or right most Indifference curve, since they represent combinations of goods providing higher levels of consumption.