You receive half of your DNA from one parent and the other half from another parent. However, this does not mean that you are receiving a perfect half from one parent and a perfect half from another parent.
For example, if my father was half Iberian and half West African and my mother was full East Asian. This does not mean that my DNA would be perfectly 25% Iberian 25% West African and 50% East Asian. I may be 10% Iberian, and 40% West African.
This is also why siblings (outside of identical twins) do not look exactly the same.