Hi Sagar,
Some I/O modules on the Nexus have over-subscribed capacity between the ports and the switch fabric e.g., the N7K-M132XP-12 has 320Gbps (32*10GE) worth of port capacity but only 80Gbps of switch fabric capacity, so an over-subscription of 4:1.
On these modules the way the capacity is shared is with the ports being split into a number of port-groups. On the aforementioned N7K-M132XP-12 module we have port groups with interfaces {1,3,5,7}, {2,4,6,8}, {9,11,13,15}, {10,12,14,16} etc., sharing the available fabric bandwidth. You're able to determine which ports are part of the same port-group with the show interface capabilities command and look for the line "Port Group Members" in the output.
For the M1 32 module the default operation is that the fabric bandwidth is shared between all members of the port-group, but the switch can be configured such that a single port of the group has full fabric capacity available to it i.e., the capacity is dedicated to that one port. This is configured using the rate-mode dedicated command within interface context. Note though that when this command is configured there's only one port of the group active so if you configure port 1 as dedicated then ports 3, 5 and 7 can no longer be used.
So what I think you're seeing in the show interfaces brief output is an indication of whether the interface is operating in Dedicated (D) and Shared (S) mode. Can you paste the output of the show interface capabilities | include "^Ethernet|Model|Port Group" and then we can see what I/O modules you have and so understand whether this is the case.
Regards
