character and block devices

We can found system's character devices and block devices from the file /proc/devices:

sriram$cat /proc/devices

Character devices:
1 mem
2 pty
3 ttyp
4 ttyS
5 cua
7 vcs
10 misc
13 input
36 netlink
124 tcpstats
128 ptm
136 pts
162 raw
180 usb
227 dump
254 megadev

Block devices:
1 ramdisk
3 ide0
8 sd
9 md
12 unnamed
14 unnamed
38 unnamed
39 unnamed
65 sd
66 sd