CSS combinator selector
Combinator selectors explain the relationship between the element you want to target and one of the other elements — whether the target's children, parents, ancestors, descendants, or siblings.
The descendant selector symbol is a space ( ) — for example, div h1. This selector targets all <h1> elements nested inside all <div> elements. The other combinators are the child selector (>), the adjacent sibling selector (+), and the general sibling selector (~).[1]
