The Meeting Summary shows you a count of discrete unique meetings, as a quick guide to how your meeting program is going.

It shows only confirmed meetings, not pending or cancelled.  It shows the total, plus a breakdown into 1x1,2x1,3x1 and Group meetings.  The pie chart  then allocates the breakdown into meeting type in graphical form. 

Below the pie chart, there is then a breakout of participation in meetings as attendee, by Role.

So Attendees, for example.  The are 265 separate appearances by attendees in meetings all together.  This states nothing about the number of meetings, but about the number of participation.   The 265 total could in theory be from 265 individual appearances in unique meetings - 1 in each.   Or in theory it could be one huge group meeting - with all 265 people in it.   We know this last idea is not the case since most of the meetings are 1x1 meetings - not simply 1 big group meeting.

But the examples here show that there were almost 2 attendee appearances (265) for every unique meeting (148) - and so the level of meeting "satisfaction" might be greater than implied by just the meeting count - since multiple attendees might take part in meetings.  These numbers given you a very good idea (without going to the detail on Meeting > Meetings).