172.31.0.0/24 is subnetted ,10 subnets what does this mean?

[swaminathan]

Thanks for your reply and I am now at least got some idea about subnet

And I got this reply which is mentioned below in quotes from other forum as well and please advise me as well about this concept

"
I agree that this is confusing. I'll try to explain that.

The classful network is 172.31.0.0/16, so if you had a subnet with any other prefix length (let it be 172.31.250.32/27) in the routing table, you would see something like

172.31.0.0/16 is variably subnetted, 11 subnets, 2 masks
172.31.130.0/24 ...
172.31.140.0/24 ...
...
172.31.250.32/27 ...

However, when there is only a single prefix length within a classful network like in your example, the output of show ip route looks a bit different. The header of the classful network specifies the prefix length, and the following network addresses don't have the prefix length:

172.31.0.0/24 is subnetted, 10 subnets
172.31.130.0 ...
172.31.140.0 ...
...

As you can see it's not about subnetting but just a notation."