Short answer
HubSpot's KB: Dropdown select and Radio select store one value from a list (they look different in forms, but behave the same on records). Multiple checkboxes stores several. Single checkbox is true or false. All three option types are enumeration properties with the same technical limits.
1. Choosing in the panel
Creating a property in my demo portal with Multiple checkboxes selected.

2. Reporting differences
Multiple checkbox values are stored together, so check how your reports and filters treat several values on one record.
3. Related
Labels vs internal names and a multi-checkbox milestone property.