This document discusses methods for calculating volumes using integration. There are three main methods - disc, washer, and shell. The disc and washer methods use the formula πr2h to find the volume of revolution around an axis, with disc used for hollow shapes and washer for shapes within other shapes. The shell method uses 2πrh and is primarily used for revolutions around the y-axis. It is important to determine the correct graph and limits of integration based on the problem.