Victory points is the count (number of points) needed for a system to become vulnerable. This is typically represented as the contested value (%). Completing plexes and battlefields earns a set number of victory points, which can be increased or decreased by the Advantage in that system.

A system needs 75,000 victory points to reach 100% contested and become vulnerable.

Currently, players earn the following amounts of victory points for completing plexes and battlefields: (subject to change)

Plex Victory Points
Scout NVY 25
Small NVY 50
Medium NVY 150
Large NVY 250
Small ADV 75
Medium ADV 175
Large ADV 300
Open 350
Battlefield 2000

Most recent changes: https://www.eveonline.com/news/view/patch-notes-version-21-05?