We survey Ozsváth-Szabó's bordered approach to knot Floer homology. After a quick introduction to knot Floer homology, we introduce the relevant algebraic concepts (A ∞ -modules, type D-structures, box tensor product, etc.), we discuss partial Kauffman states, the construction of the boundary algebra, and sketch Ozsváth and Szabó's analytic construction of the type D-structure associated to an upper diagram. Finally we give an explicit description of the structure maps of the DA-bimodules of some elementary partial diagrams. These can be used to perform explicit computations of the knot Floer differential of any knot in S 3 . The boundary DGAs B(n, k) and A(n, k) of [6] are replaced here by an associative algebra C(n). These are the notes of two lecture series delivered by Peter Ozsváth and Zoltán Szabó at Princeton University during the summer of 2018.A powerful paradigm in computer science is the so called Divide et Impera. It consists of dividing a complicated problem into smaller subproblems in order to solve them individually. In topology this translates to the cut and paste philosophy. More specifically: suppose that one wants to compute an invariant D of some space X, then one can divide X into pieces P 1 , . . . , P N and can compute some sort of related invariant I for the pieces, and develop some gluing formula expressing D(X) as a function of I(P 1 ), . . . , I(P N ). A typical example is when D(X) is the fundamental group: in this case the invariants I(P i ) are some inclusion maps, and the gluing principle is the Seifert-van Kampen Theorem.In four-manifold topology, cut and paste techniques to compute Seiberg-Witten invariants were pioneered in [2] and eventually led to the definition of the Monopole Floer homology groups by Kronheimer and Mrowka [3]. In the case of the Heegaard Floer three-manifold groups an implementation of the cut and paste approach first appeared in [4]. In this work Lipshitz, Ozsváth and Thurston associate to three manifolds with boundary Y 1 and Y 2 a type D-structure CF D(Y 1 ) and awhere, whatever these algebraic structures are, is some sort of tensor product operation that takes as input a type D-structure and an A ∞ -module, and gives back a chain complex.Ozsváth and Szabó developed a similar construction in the setting of knot Floer homology [6]. Given a knot K ⊂ R 3 one can split it into two parts by means of a two-plane z = t. Denote by K [t,+∞) = K ∩ {z ≥ t} the portion of K lying above the plane z = t. Similarly denote by K (−∞,t] = K ∩ {z ≤ t} the part lying below it. In [6] Ozsváth and Szabó associate to K [t,+∞) and K (−∞,t] a type D-structure DF K(K [t,+∞) ) and an A ∞ -module AF K(K (−∞,t]) ) so that CF K(K) = AF K(K (−∞,t]) ) DF K(K [t,+∞) ) .More generally, they develop some sort of Morse theoretic approach one can apply to compute knot Floer homology: given t 1 < t 2 they associate toThe scope of these lecture notes is to survey the algebraic language of A ∞ -modules, type D-and DA-structures, and sketch Ozsváth and Szabó's recent construction. We will only a...