The selectors can be nested for ease of writing and reading. This can help organize code in a way that like selectors are together. It also keeps us from having to repeat strings of selectors. A quick example would be:
You can even go deeper if you would like. Let's take a look at 4 levels deep (the suggested maximum depth for Sass).
Using the & Symbol
There is a helper character that makes referencing parent selectors much easier. This character is the ampersand (&) symbol.