Interpreting the show interface Command

Router#show interface serial 0/0	Displays status and stats of interface
Serial 0/0 is up, line protocol is up	First part refers to physical status. Second part refers to logical status
...<output cut>...
Possible output results:
Serial 0/0 is up, line protocol is up	Interface is up and working
Serial 0/0 is up, line protocol is down	Keepalive or connection problem (no clockrate, bad encapsulation)
Serial 0/0 is down, line protocol is down	Interface problem, or other end has not been configured
Serial 0/0 is administratively down, line protocol is down	Interface is disabledshut down