When creating new fields, i.e. columns, within Affinity you will have the option of setting it as a Global or List specific field. This setting determines whether the column will exist amongst all the lists or just a specific list. Keep in mind, once a field is defined as list specific or global it can not be changed.
A global field will exist across all the lists that you have access to and will display the same information for an entity across all these lists. Common examples of global fields: Location, Description, or Title etc.
A list field will exist only on a specific list. This allows you to recreate this field in different lists and display different values per list. Common examples of list fields: Owner, Fund Name, or Investments etc.