What is a node?
A node is a point in a network. It is at this node where lines and pathways intersect and/or branch out from. It can be said that a node is somewhat like a junction, where traffic intersects, mergers and separates again.
Officially speaking, a node is either a redistribution point or a communication endpoint. Basically, this means that information either travels through here or ends up here.
In a communication network, where all the devices are accessible, these devices are all considered to be nodes. It is at these devices, where the information is merged, accessed and transferred from. Basically, nodes act as major centers through which Internet traffic is typically routed.