This page is here to give you a basic view of what a packet looks like, in the general case. A packet is the basic unit of data transfer in a networked environment.
Packets are individual chunks of data, flowing in a single direction.
Once they reach their destination, they cease to exist. There are different kinds of packet floating around various networks. Technically, a particular packet type is usually found at a specific level of nesting. A packet that travels on top of nothing but a Layer 1 packet, is a Layer 2 packet type. This is the ethernet packet.