IP address
An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication.
An IP address serves two principal functions: host or network interface identification and location addressing.
Optical IP Switching
Currently a packet has to traverse a certain number of routers, before reaching its destination and the network routers must analyze each packet and forward it towards the direction of the destination node. 
However, since a flow is defined as a sequence of packets going from the same source to the same destination, if the router recognises the flow it could create a short-cut by creating a “switched” connection allowing all the packets belonging to the same IP flow to proceed directly towards the correct direction without being analyzed one after the other. This general idea is known as IP switching.