A collection or group of various things or sorts.
(source: thefreedictionary.com )

The product assortment is the whole collection of products that a retail store carries. Whereas some stores may carry a deep and wide assortment in their merchandise mix, such as a large online retailer, other stores may have a shallow and narrow assortment*, such as a small chocolate store. The aim of merchandise planning is to provide the store’s customers a highly desirable merchandise mix as well as to decide which products can bring in most profits and which products should be kept out from the merchandise mix.

(source: mbabrief.com )