Definition 1: being an integer (a number with no fractional part)
Example: "there are only integral changes" means any change won't have a fractional part.
Definition 2: the result of integration.
Integration is a way of adding slices to find the whole.
It can be used to find areas, volumes, central points and many useful things.
The slices head towards zero in width ("dx"), and in many cases we can find a formula that gives us an exact answer.
