What is the purpose of the built in checkbox in the list view?

Hi there!

The checkbox you're referring to is called a prefix. Prefixes are essentially a checkbox field that provides an easy way for you and other colleagues to know when an item has been completed. 

To add or remove a prefix field in List view, access the Customize rows setting and choose the desired option:

You can see a checkbox field prefixed to the first field of your lowest-level table (and your nested records, if that’s enabled). This checkbox field’s name will not be visible and will be indented alongside nested records.

Hope this helps explain things a bit more clearly!

Actually, I think you may be referring to the record checkbox instead. This works much like it does in a grid view where you can select multiple records at one time and perform an action such as Duplicate record, Create record template, Apply template, Add comment, Copy record URL, and Delete record. To view the options, select a record by clicking the checkbox and right-click:

If you select multiple records and then right-click, you can delete multiple records at once:

 Please let me know if you're referring to something else!