Communities vs Groups - a comparison

I noticed there are Commiunities  and Groups on the site.  I was not sure what the difference is, so I did a little comparison. Here are my observations about them and how they differ initially

Find->Groups
https://community.intersystems.com/find/group
 - lots of whitespace layout(need to scroll to see all items)
 - Listed in an unknown order
 - shows Tags for each group (if they have any), Tags clickable
 - shows the owner/creator of the group and a date (of creation?)
 - 12 Groups in list
 

Connect-> Communities
https://community.intersystems.com/connect/communities
 - Good tight list with thumbnail image (see almost all on one screen)
- Listed Alphabetically.
- Shows # of posts, with the last post time/date
 - 11 Communities in list - missing the iknow "Group"

(I am not sure why iKnow is not in the community list - oversight?)

If you click on any of the 11 Communities/Groups in common between the two pages, you end up at the same place!
Example - click on Caché from either of these pages and you end up at the same place
https://community.intersystems.com/group/caché

Is there any real functional or organizational  difference or if it is just a misnaming mistake? 

I prefer the Communities view of the list as it provides a more compact view and shows me info about the number of posts and when the last post occured.

If there is no difference between communities and groups, shouldn't we pick one name (community or group) and use it throughout the site and navigation?

thoughts?