The difference between Tasks and Lists is that Tasks can have a set Start and End Date, can be assigned to one or more Assignees, can be Recurring, and have Reminders so that you can receive notifications.
A List is merely a collection of items listed, which each can have additional information through a description and attachments, and can include checkboxes to check of and get timestamped. You are able to duplicate both Tasks and Lists.
The way Tasks and Lists work together, is that you can load a List within a Task, and also convert any List items into a Task (if you want to set a due date, assign it to one or more assignees, make it recurring, and/or set one or more reminders).
