How to have a menu like this (don't know how to describe it. Example:amazon )
 

I want to google this but just have no idea what to search for. Maybe because my English is not good enough....

I wanna have a menu like the one on homepage of amazon.com (Please see attachment). The function I like is when the mouse is moved to the menu, the next level menu will slide out.
This is probably not related to this theme. But I just hope someone can tell me what is this and what to look for.

Thanks

you will need to look for a plugin or do some custom coding

Thank you, Juggledad. Do you know what could be the keyword for me to search for to find the plugin or coding method?

sorry but no