In Elixir, there are several types of variables that can be used to store and manipulate data. Here are the most commonly used variable types in Elixir:

* Atoms : Atoms are constants that represent their own name. They are identified by a leading colon (`:`) followed by a sequence of characters or symbols. Atoms are often used as identifiers, flags, or keys in maps. Examples of atoms in Elixir are `:ok`, `:error`, or `:name`.

* Numbers : Elixir supports several numeric types, including integers and floats. Integers can be written using standard decimal notation, as well as hexadecimal (prefixed with `0x`), octal (prefixed with `0o`), and binary (prefixed with `0b`) notations. Floats represent fractional or floating-point numbers, such as `3.14` or `1.0e-6`.

* Booleans : Booleans represent logical values and can have two possible states: `true` or `false`. Booleans are commonly used in conditional statements and logical operations.

* Strings : Strings represent sequences of characters and are enclosed in double quotes (`"`). Elixir supports Unicode strings, allowing you to work with text in various languages and character sets. String interpolation is also available using the `#{}` syntax to embed variables within a string.

* Immutable Variables : Elixir variables are immutable by default, meaning that once assigned a value, they cannot be changed. When you assign a new value to a variable, it actually creates a new variable binding rather than modifying the existing value. Immutable variables promote functional programming principles and help ensure code reliability.