What does $\min\sum\dots$ indicate? What does "min" indicate infront of a sigma sign?

$$\min \sum_{e\in E} c_e x_e$$

Source: https://www.math.unipd.it/~luigi/courses/metmodoc1718/m08.01.TSPexact.en.pdf

The $c_e$ are some constants, the $x_e$ are variables that satisfy some constraints and you are minimizing the sum $\sum_{e\in E} c_e x_e$ over all feasible choices of the $x_e$.
