IP Address and Subnetting.

CIDR representation of the address and subnet mask.

In this case your address, 192.16.30.15/24 is showing that the first (/24 bits of your address 192.168.1.15 represent the network and the last 8 bits of the address 192.16.30.15 represent the host(s).

CIDR addressing is a more efficient scheme of subnetting, allowing for better utilization of available ip addresses.

/24 means first 24 bit for network
ie 11111111.11111111.11111111.00000000 So mask is 255.255.255.0

Its basically equivalent to:
IP: 192.16.30.15
Mask: 255.255.255.0

Which is a Class C network (http://www.support.psi.com/support/common/routers/files/class.html)