<h2>Answer :</h2>
As we know, that all squares are quadrilateral but its converse is not necessarily true.
Set of Quadrilaterals is a super set of set of squares.
i.e. set of squares ≤ set of quadrilaterals.
From the picture, we can know that quadrilaterals consists of all the squares and square is a type of quadrilateral. All the squares belong to quadrilaterals, while not all the quadrilaterals belong to squares.
[It's important to have a good understanding of venn diagram as it illustrates the connection between things in it]