Difference between Hoverextender andhovermenuextender??

Hi

whats the difference between the hoverextender and hovermenuextender? When would i use one and not the other?

What i want to achieve is this: I havea griview that displays data in each row. I want to be able hover over each row and disply additional notes specific for that rowitem. An d inthat same popup thingy be able to edit and save those notes. Any tips on how to do this or any samples that i am not awre of.

Anyone?
HoverExtender is a simple wrapper that makes it easy to use the HoverBehavior (client-side script for detecting mouse hovers). HoverMenuExtender uses HoverExtender and adds support for displaying UI when the hover happens. HME is more of a usable control while HE is more of a building block.
thanks