/32 means it's a single address not a network or range of addresses.
IPv4 has 32 bits. These can be divided into network address (the first bit) and machine addresses (the second bit)
So a /32 address is unique. Its the same as a mask of 255.255.255.255
all 32 bits are used for the machine.
In a /28 address the first 28 bits define the network and all traffic for that can be routed to it, then the last 4 bits split up the traffic internally. network / machine ie 28 / 4 bits.
A /28 address would use the last 4 bits (8,2,4,1) for 14 network devices
Network: 192.168.0.0/28 11000000.10101000.00000000.0000 0000 (Class C)
Broadcast: 192.168.0.15 11000000.10101000.00000000.0000 1111
HostMin: 192.168.0.1 11000000.10101000.00000000.0000 0001
There's a calculator at http://jodies.de/ipcalc
to play with
MaxDSL - goes as fast as it can and doesn't read the line checker first.