RAM :
Temporiry memory only contain runing configuration.
NVRAM :
Permananet memory contain all startup configuration
FLASH :
Conatin router IOS(internetwork Operating System).
ROM :
Just conatin the information like bios.
Interface Ports :
Mainaly used send and receive a packets.
Ethernet
Fast Ethernet Ports
Serial Ports
t1 : 1.544 mbps ( us )
e1 : 2.048 mbps ( asia country )
Console Port :
Access the router using physically plug the console cable
Auxilary Ports :
Access the router but outside of network using modem
SMPS :
Switch mode power supply ( maintain the power section )
