Feynman diagrams for one- and two-particle Green’s functions for electron–electron interactions are considered in detail, starting from the interaction representation and Wick’s theorem in the general non-zero-temperature case. It is shown that the perturbation expansion can be written via determinants of increasing order built from non-inetracting Green’s functions. We prove general linked cluster theorem, enabling one to drop the normalising denominator and use only connected diagrams in the expansion of the Green’s function. Next we clearly explain why only topologically equivalent diagrams need to be considered, before formulating general diagrammatic rules for the Green’s function and the self-energy. The ideas of a partial summation via skeleton diagrams and the vertex function are then discussed. Random phase approximation and the grand potential are studied for the uniform system within the jellium model. Finally, a diagrammatic technique for the two-particle Green’s functions is discussed, leading to the kernels and Bethe–Salpeter equation. As an example, the diagrammatic expansion for the dielectric response within the jellium model is developed.