Create a Fixed List when you want an individual customer or specific group of customers to access a particular promotion or receive a targeted push notification. Customer's can only be added to and removed from a fixed list manually.
A Smart List updates dynamically based on the filters applied to that list. As customer's readh the filter (i.e their total spend) they are automatically added to the Smart List and well see the relevant promotions or receive the relevant broadcast. Additionally, if they no longer meet the filter (i.e current points = 100) they are automatically removed from the list.