# Variables

## What is a Variable?

A variable is essentially a label for a value. They contain a piece of data. A variable can contain any data type. For instance, a variable can contain a list.

## Why Should I Use Variables?

Variables help improve readability of code, and can reduce the amount of coding needed.

Say that you need to use a string again and again, you could just write the string each time, but then if you wanted to change the string, you would need to change each mention of the string. Instead, you can use a variable that contains the string. Meaning that if you wanted to change the string, you would only need to change it once.

## Using Variables <a href="#using-variables" id="using-variables"></a>

To use a variable, the variable must first be defined. After that, it may be referenced or changed.

### Defining Variables <a href="#defining-variables" id="defining-variables"></a>

To define a variable, you simply write it's name followed by an equals sign and then the value the variable will have.

```python
my_variable = "A simple string"
```

Now, the variable, "my\_variable" may be called from the code.

### Changing Variables <a href="#changing-variables" id="changing-variables"></a>

Changing a variable is a lot like defining it, in fact, it's no different.

```python
my_variable = "A simple string"
my_variable = "A different string"
```

The first line will create the variable and give it the value, and the second line will change the value of the variable.

### Referencing Variables

To reference a variable, you simply write the name of it where you would like it to be used.

```python
my_variable = "A simple string"
print(my_variable)
```

This will print, "A simple string" to the terminal.


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