# Overview

The base R environment has options for approximating many of the properties associated with probability distributions. This is not a complete discussion, and a more complete list can be found within the R environment using the `help(Distributions)`

command. In this chapter, we will discuss how R can be used to approximate distribution functions, how to approximate cumulative distribution functions, how to approximate inverse cumulative distribution functions, **Random Number Generation** (**RNG**), and sampling.

The commands used for the first set of topics have a common format, and each command has the form of a prefix and a suffix. The suffix specifies the distribution by name. For example, the `norm`

suffix refers to the normal distribution. A list of the distributions available in the base R installation is given in *Table 1*. The prefix is one of the following:

`d`

: This determines the value of the distribution function, for example,`dnorm`

is the height of the normal's probability distribution...