Given two manifolds M and N, an embedding of M in N is basically an injective map f: M --> N such that its derivative is injective everywhere. Two embeddings are the same or isotopic if one can "distort" one into the other without "breaking it". A basic question one can ask is the following: how many different ways can one embed M in N? This talk will discuss this question. In particular, we will see that when M is a bunch of Euclidean spaces and N = R^d, the set X of isotopy classes of embeddings of M in N is a finitely generated abelian group. We will also see that X can be modeled by some graph complex whose graphs are similar to Feynman diagrams from particle physics. The main tool we use is the theory of manifold calculus of functors.