A network packet is a formatted unit of data carried by a packet-switched network. Computer communications links that do not support packets, such as traditional point-to-point telecommunications links, simply transmit data as a bit stream.When data is formatted into packets, the bandwidth of the communication medium can be better shared among users than if the network were circuit switched.he routing of network packets requires two network addresses, the source address of the sending host, and the destination address of the receiving host.