Lists come in two types: static lists (regular lists) and dynamic lists.
Depending on the type of list, the content data is edited in different places. If you're not sure which type of list you want to edit, follow the steps below to check.
How to check the list type
Select the entire list you want to check.
Open the Layers panel and select the element with the light blue list icon
next to it. On the canvas, the list icon 
appears at the top left of the selected element.
Open the [Data] tab in the right panel. If the right panel is closed, open it first.
Check the dropdown label at the top of the [Data] tab.
If it shows [Connect data]
The list is a static list (regular list).
Refer to the following articles to edit the list.
If a data source ([CMS], [API], [RSS], etc.) is shown
The list is a dynamic list.
Refer to the relevant article for your data source below to edit the list.
If it shows CMS
The list is connected to CMS content from Studio CMS. Refer to the following articles to make your edits.
If it shows API
The list is connected to content data from an external service retrieved through an API. Refer to the following articles to make your edits.