Squares are often seen as the best type of four-sided shape, called a quadrilateral. Here are some reasons why:

1. Equal Sides and Angles: All four sides of a square are the same length, which we can call $s$. Each angle inside the square is exactly $90^\circ$. This makes squares very useful in things like tiling floors and building designs.

2. Symmetry: A square has four lines of symmetry. This means if you fold it, both sides will match up perfectly. It also has rotational symmetry, meaning if you turn the square by $90^\circ$, it looks the same. Not many other four-sided shapes can do that!

3. Special Case of Other Quadrilaterals: Squares are a special type of rectangle (where all sides are equal) and a rhombus (where all angles are right angles). Because of this, squares can use rules from both types and have diagonals that meet at right angles.

4. Area and Perimeter: To find the area of a square, you just multiply the length of one side ($s$) by itself, so that's $s^2$. To find the perimeter, you add up all the sides, which equals $4s$. These simple calculations make them easy to work with in math.

In conclusion, squares mix equal sides, symmetry, and easy math, which is why they are considered the best of the four-sided shapes!