A label in Google Contacts works like a tag or folder you attach to a contact. It helps you organize people into categories such as “Clients,” “Vendors,” or “Family,” and one contact can carry several labels at once.

A contact list is the collection of contacts that share the same label. For example, if you create a label called “Team,” then all the people you add to that label become part of your Team contact list. You can then use that list to email or share with everyone in it at once.

A group is slightly different. In Google Groups, it is not just a list of people, but an entity with its own email address, such as team@company.com. Sending a message to that address will reach all members of the group. However, in everyday use, some people use the word “group” simply as another way to describe a contact list in Google Contacts.

In short, labels are the tags you assign, contact lists are the sets of people under those tags, and groups are usually email-based communities with their own group address.

Label	Contact List
Google Group