Duffels are rectangular bags with handles and typically a shoulder strap. Duffels are often made of nylon or leather and used for short trips or commonly used as a gym bag.
About Luggage:
Luggage is any number of bags, cases and containers which hold a traveller's articles during transit. Types of luggage include suitcases, duffel bags, and tote bags. Today many types of luggage have wheels as an added convenience.
About Sets:
Sets refers to any type of articles of clothing or group of things which are considered to be of the same kind and that can be paired together and are so used. Layettes are one example of a group or set of articles of clothing.