A Digital Contact List is, as defined, a list of all the contacts you wish to connect to (including Talk Groups) comprised of a "Contact Name", "Call Type", "Call ID" and "Call Receive Tone".
The "Contact Name" is just human readable text describing the contact, the "Contact Name" is displayed on the radio along with additional information when the radio receives that contacts ID.
"Call Type" which can be a "Group Call" if the contact is a Talkgroup or a "Private Call" if the contact is a single person or radio or an "All Call" which covers both of the previous two.
We generally don't use "All Call" in amateur radio because it isn't necessary to our communications.
"Call ID" is the numeric ID hat is assigned to the contact, talkgroups and single users are all assigned a specific "Call ID" that is associated with that TG or person/radio.
"Call Receive Tone" allows you to set the radio to activate a "tone" if the radio receives the ID for that contact as an alert that the contact is calling. Probably not very useful for TG's but it might be handy if your buddy is calling you direct and you want to be sure not to miss his or her call.
73,
Ken - KA8OAD