Questions on (ordinary) differential equations. For questions specifically concerning partial differential equations, use the (pde) tag.
A differential equation is any expression that relates the values of a collection of functions and their derivatives, as well as some coefficients. One may be asked to solve (symbolically or numerically) or estimate the solution to a differential equation. Usually, they appear as the result of a mathematical model for a physical phenomenon.
This tag is intended for ordinary differential equations, i.e., the differential equations which contain only derivatives w.r.t. one variable and not partial derivatives.