Isoquant curve represent the various combinations of two inputs that produce the same amount of output. It is also called as iso-product curve, equal-product curve or production indifference curve. In other words, isoquant may be described as a curve which shows the different combinations of the two inputs producing a given level of output.
Linear Isoquant: This type has perfect substitutability between factors of production, that is a given output can be produced by using only capital or only labour or by a large number of combinations of capital and labour.
Input-output isoquant: If we think strict complementary between the inputs, weget input-output isoquants. When there is only one method of production for any commodity, its isoquants take the shape of right angle.
Kinked isoquant: Assumes limited substitutability of capital and labour. There are only a few proces available for producing any commodity , substitutability of factors is possible only at bends.
Smooth convex isoquant: Continuous substitutability of capital and labour only over a certain range, beyond which factors cannot be substituted for each other. Isoquant appears as a smooth curve convex to the origin.