The difference between both Array formats
Using the ARRAY custom field on Honeycommb you can either decide if you'd like the field to be a multiple check-box or a single select radio button. Visually and functionally to the user, the two fields are different:
Using a single-select, users are allowed to select only ONE option as a radio button from the list of provided answers.
Using the multi-select, users are allowed to checkboxes from a drop-down list of possible answers that they can use to indicate results to an answer.
TIP: When creating an array, you can make the selection for either of these two different formats by using the validations section in the field editor creator.
You'll want the validation for maximum length to equal 1
The maximum is not required to have a multi-select. If you add maximum value, then it will still be a checkbox but users will have the ability to select the max amount of checkboxes provided.