Archetypes are the Classes of Ring Runner. A ship's Archetype determines how a ship plays by determining what Nodes that ship has available. Each Archetype has gives a Ship access to three unique Nodes (or two in the case of some low-rank ships).
Veterancy is the increase in power your ship gains for killing manned enemy ships. Turrets, Drones or Decoys will not grant veterancy if you kill them.
Each Archetype has a different Veterancy Node, each of which currently contains one ability that scales, and several other "simple" passives.
With that scaling ability equipped, each kill grants an effect that can stack 5 or 7 times depending on your Archetype.
The size of the Common Nodes are also affected by Archetype eg. Fighters have a small shield Node, but a large Auxiliary Drives node.