A combinator is something that explains the relationship between the selectors,A CSS selector can contain more than one simple selector. Between the simple selectors, we can include a combinator,The descendant selector matches all elements that are descendants of a specified element,The child selector selects all elements that are the children of a specified element,The adjacent sibling selector selects all elements that are the adjacent siblings of a specified element,The general sibling selector selects all elements that are siblings of a specified element.