What does the '&' selector select?

Question

In this codepen there is a css selector &:hover what does that selector match?

Answer 1

One usage that is less widely known is you can add the ampersand to the end of a style so the parent selector becomes the child.

eg:

 h3
   font-size: 20px
   margin-bottom: 10px

 .some-parent-selector &
   font-size: 24px
   margin-bottom: 20px

becomes,

  h3 {
    font-size: 20px;
    margin-bottom: 10px;
  }

  .some-parent-selector h3 {
    font-size: 24px;
    margin-bottom: 20px;
  }

you can read more about & use here

http://thesassway.com/intermediate/referencing-parent-selectors-using-ampersand