Cisco Port security is an important feature to most of my customer. Especially Software development companies and BPOs are the constant customer types asking for this feature to restrict devices connecting to their network.
Cisco Port security is to limit the devices that are connecting to the Wired network via switches. This feature checks for MAC address of the device that has just accessed the switch port and verifies whether that device is allowed to connect wired network or not. The wireless equivalent of this feature is MAC address Authentication. The number of addresses the feature accepts is equivalent to the maximum limit of MAC address of the switch.