Washer Method:The washer method is another technique used to find the volume of a solid of revolution, but it considers both inner and outer radii instead of just one radius like the disc method.
Shell Method: The shell method is an alternative approach to finding the volume of a solid of revolution by integrating cylindrical shells instead of discs.
Cross-sectional Area: Cross-sectional area refers to the area formed when a plane intersects with a three-dimensional object. In the context of the disc method, it represents the area of each infinitesimally thin disc.