The products catalog lists ALL of the items in HQ and allows for single and batch editing of item attributes. It is exactly like the Product Manager page in the Local S2k version except only Core/HQ items will appear in HQ and in local it will have a mix of flex/local items and core/HQ items.
NOTE: All changes made to the attributes of this core/HQ pricebook will immediately be reflected at the local S2k for all sites that are managed by the HQ database. This includes adding new items, changes to short or long description, sub-department, SRP or fees.