What's the difference between fixed choice lists and dynamic choice lists?
A fixed choice list and a dynamic choice list are similar in that the ultimate goal of both types of choice lists is to generate a field with a list of values.
For a fixed choice list, the field's specific list values are populated from a lookup type that you select when you define the field. The list displays in a single column and doesn't change.
A dynamic choice list, meanwhile, is populated from an existing object's actual data, which you can add filters to. Based on how you define the field, the list is dynamically populated at runtime and its values can change depending on the user's context. In addition, you can add more columns to the dynamic choice list field to assist your users in making a selection at runtime.