Switch stacking, known as Cisco StackWise on Cisco products, is a technology that connects multiple switches into one logical switch. By using stacking technology you get a decrease in administrative overhead and less blocked ports from Spanning-tree Protocol (STP).
You can add switches to gain port density and you can add them over time. This provides room to grow and decreases up front costs. Since the switch now appears as one logical switch, you only need to assign one management IP to it rather than individual IPs to each access switch. The administrative burden is lessened as well as you can go into one interface rather than into individual management consoles.
There is a master switch, called the stack master (which is elected), that manages the stack. The remainder of switches communicate via special interconnect cables. EtherChannel can still be used and will eliminate STP. StackWise technology can support up to nine switches.
To find how the stack ports are connected.
Switch#show switch stack-ports
To see the switch neighbors.
Switch#show switch neighbors