A second-degree connection is a person you do not know directly, but can reach through someone you do: a friend of a friend. You cannot see or recall these connections on your own, yet they are where the richest warm intro opportunities sit.
Your first-degree connections are anyone you have a direct link to: people you have worked with, your LinkedIn connections, people you have emailed. Your second degree is everyone they know, which you cannot track by memory. That second layer is the bulk of your extended network, and it is usually many times larger than your direct contacts.
Most buyers are not in your first degree, but a surprising number are one trusted hop away. Surfacing those hops is what pathfinding does, and closing the gap between the paths you have and the ones you can see is the point of fixing the network gap.
Via makes your second-degree connections visible. It looks past your direct contacts to surface the friend-of-a-friend paths into your target accounts, ranked by how strong each one is, so you can act on routes you would never find manually.