A punant square, as we'll see in just a moment, is actually a tool that is used in genetics. And it helps scientists uncover the potential possibilities of the genotypes of the offspring that are formed in some given mating process, in some given crossing process. So when we cross two individuals or when we cross two organisms, that simply means we mate those two organisms to produce some offspring. And what the Ponnet square allows us to do is it allows us to basically uncover the type of genes that will be found within that given individual. Now, before we actually examine what the Ponnet square is and how we can use it and what information it provides us with, let's actually discuss four important terms that we must know whenever dealing with pundit squares. So we have something called heterozygous and something called homozygous.