In the context of DFT Jacob’s ladder is a strategy to find the divine functional, meaning the exact exchange-correlation functional. It consist of 5 methods that are increasingly better the higher on the ladder, but every next method builds on the previous methods. The first rung of the ladder is the local density approximation (LDA), the second rung is the Generalized Gradient Approximation (GGA), the third rung is the meta-GGA, the fourth rung treats the exchange as exact and the fifth rung also treats the correlations as exact, and thus the divine functional is found.