There are a number of classifications of space in Eve, listed below for reference.
Known Space
Known space, AKA K-space and normal space, is the classification of space which includes Empire and NullSec, both seperately split into different classifications.
Empire
HiSec
LoSec
NullSec
NPC NullSec
NPC NullSec is null-security space where the sovereignty is claimed by NPC factions, similar to normal 'Empire' space, therefore cannot be claimed by capsuleer alliances.
Regions classified as NPC NullSec:
- Curse, claimed by Angel Cartel
- Great Wildlands, claimed by Thukker Tribe
- Outer Ring, claimed by Outer Ring Excavations
- Stain, claimed by Sansha's Nation
- Syndicate, claimed by Intaki Syndicate
- Venal, claimed by Guristas
Claimable NullSec
W-space
Wormhole space, aka W-space is the name given to systems only accessible through Wormholes. these systems are not interconnected through stargates, and no stations are available in them. On top of this, wormholes also contain 'anomalies' which adjust various statistics on your ship.