Explanation:

The human population growth follows an S-shaped growth curve. This type of growth curve is also known as a logistic growth curve. The S-shaped curve is named so because of its S-like shape, which is formed due to the limiting factors that regulate the population growth.

Factors affecting population growth:
The population growth is mainly influenced by two factors - biotic and abiotic factors. These factors are responsible for regulating the growth of the population, and hence they determine the shape of the growth curve.

Biotic factors:
Biotic factors are the living factors that influence population growth. Some of the important biotic factors that regulate population growth are:

- Competition for resources
- Predation
- Parasitism
- Disease
- Mutualism
- Commensalism
- Migration
- Birth rate
- Death rate

Abiotic factors:
Abiotic factors are the non-living factors that influence population growth. Some of the important abiotic factors that regulate population growth are:

- Climate
- Soil nutrients
- Water availability
- Light
- Temperature
- pH

Logistic growth curve:
The S-shaped growth curve is a result of the logistic growth model, which is used to describe the growth of populations that are limited by resources. In the initial stages, the growth is exponential, and the population size increases rapidly. However, as the population size approaches the carrying capacity of the environment, the growth rate slows down, and eventually, the population stabilizes at the carrying capacity. The carrying capacity is the maximum number of individuals that an environment can support.

Conclusion:
Thus, the human population growth follows an S-shaped growth curve, which is influenced by both biotic and abiotic factors. The logistic growth model is used to describe the growth of populations that are limited by resources.