1 A non-adaptive routing algorithm which is used for routing data stored in packets. This algorithm involves a computer sending the packet out on every transmission line that it is connected to, apart from the line it emerged from. In this way a packet is guaranteed to traverse the current shortest path in a network. When such a packet arrives, all the duplicate packets are then discarded. This is an expensive form of routing as it can increase network traffic considerably. However, it has its uses: for example, in a military network where robustness and reliability are required. A more efficient version of flooding is known as selective flooding.
2 Used to describe a denial of service attack, when a computer is bombarded with messages. See, for example, SYN flooding.