What information does the show interfaces command provide?

Full per-interface detail — Layer 1/2 status, hardware type and MAC, IPv4 address, MTU, bandwidth, duplex/speed, and traffic counters — used when troubleshooting beyond the simple brief summary.

show interfaces Command Output:

Displays detailed statistics for all interfaces. Key information includes:

R1# show interfaces gig0/0/0
GigabitEthernet0/0/0 is up, line protocol is up
  Hardware is ISR4321-2x1GE, address is a0e0.af0d.e140
  Description: Link to LAN
  Internet address is 192.168.10.1/24
  MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Full Duplex, 1000Mbps, link type is auto, media type is RJ45
  ...
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec

Key fields:

Go deeper:

• Cisco IOS (Wikipedia) — the IOS command set, of which show interfaces is the detailed per-interface diagnostic.