Taxonomy of Probability Distributions according to the number of its peaks
One way to categorize Probability Distributions is based on the number of its peaks
Unimodal Probability Distributions
The Unimodal Probability Distributions have one peak as the Normal Distribution (blue one) but there are other types of Probability Distributions with one peak such as the Poisson distribution (Orange color), the Triangular distribution (Green color) or the Uniform Distribution (or Rectangular Distribution, Grey color).
The Poisson Probability Distribution is a distribution which represents random events that can happen into specified intervals of time or space (volume, distances, area) and the occurrence rate of these events is known. An example of a Poisson Probability Distribution can be the number of cars or bicycles that pass by outside your house.
Note that in the Uniform Distribution, any value of a random variable has equal probability. An example that can produce a Uniform Distribution is tossing a coin. The probability of the result by tossing randomly a coin -head vs tail- is very equal.
Multimodal Probability Distributions
The Multimodal Probability Distributions have more than one peak such as the Bimodal Probability Distributions (two peaks). A special case of Bimodal Probability Distribution is the one that is a mixture of two Normal Distributions.
Example of Bimodal Probability Distributions (Multimodal Probability Distributions) and other Multimodal Probability Distribution examples