The role of differential equations in the process of calculating Feynman integrals is reviewed. An example of a diagram is given for which the method of differential equations was introduced, the properties of the inverse-mass-expansion coefficients are shown, and modern methods based on differential equations are considered.

22 pages; contribution to the proceedings of the International Conference "Antidifferentiation and the Calculation of Feynman Amplitudes" (4-9 October 2020, Zeuthen, Germany). arXiv admin note: text overlap with arXiv:2004.06625