Decendant combinators combine two selectors such that are descendant.
In the example below, we are matching only the <p> elements inside an element with a class of .box.
Text in a .box class
Text not in a .box class
Child Combinator matches only those elements matched by the secound selector that are direct children.
is used to select something if it is right next to another element at the same level of the hierarchy.
The fist imgage has a border, the secound does not.
to select siblings of elements even if they are not directly adjacent,
then you can use the general sibling combinator