Areas are measured in terms of the number of squares that could fit within a region. However, the smaller the squares, the more of them there will be, and vice versa.
A square that is 1 m along each side is said to have an area of 1 m2. A very common mistake is to think that this is the same as 100 cm2.
As you can see, a square 10 cm along each side contains 10 × 10 = 100 cm2. This is most definitely not 1 m2!