Line integral

A line integral is a way of measuring how much something changes when you move along a line. Think of it like you are tracing along a line, like you would with a finger. As you trace along the line, you are measuring a number, which can be seen as the height of the line or the speed at which you are moving. This number changes as you trace, and a line integral tells you how much the number has changed by the time you reach the end of the line.