What are Snap-In Modules?
Snap-In Modules are pre-built sections of the page which perform specific functions. Examples are the Search Box, Browse by Category, Browse by Manufacturer, Side Column Shopping Cart, Sale Products, and even Custom HTML. Some controls are typically only used on the side columns, while others are used only on the home page. You can view a list of snap-in modules available on each page type within the Themes area. Browse to Themes > Active Themes and select any page type (Home Page, Category Page, Manufacturer Page etc) and you can view a complete list of snap-in modules available for that page type.