In a population, what is the unrestricted reproductive capacity known as?

Biotic potential

Unrestricted reproductive capacity is called biotic potential. Biotic potential is defined as the physiological capacity of organisms to produce their offspring under natural conditions. It is also called reproductive potential. In nature, the biotic potential of organisms is enormous but all the organisms do not survive due to the lack of food and space. There are also a number of diseases and the predatory organisms that feed on other organisms.

Carrying capacity is the maximum number of individuals of a population a habitat can hold.

Birth rate or natality is the rate at which new individuals are added to a population by reproduction.

Fertility rate is the average number of individuals that an organism produces during its lifetime.