"Supports multi-host connectivity for each USB port or group independently"
This means that each USB port can be added to a group. Each group can be accessed by 1 person at a time.
For example, an 8 port AW USB PLUS can have USB ports 1-4 in group 1, 5-6 in group 2, 7 in group 3 and 8 in group 4.
At the same time,
Person 1 can connect to group 1 and 4
Person 2 can connect to group 3
Person 3 can connect to group 2
Multiple clients cannot access the same group at the same time.