There are 10 different types of Anomaly Class Class 1 (easiest)-Class 10 (hardest).
Class 1 = (Faction) Hideaway or Drone Cluster (easiest)
Class 2 = (Faction) Burrow or Drone Collection
Class 3 = (Faction) Refuge or Drone Assembly
Class 4 = (Faction) Den or Drone Gathering
Class 5 = (Faction) Yard or Drone Surveillance
Class 6 = (Faction) Rally Point or Drone Menagerie
Class 7 = (Faction) Port or Drone Herd
Class 8 = (Faction) Hub or Drone Squad
Class 9 = (Faction) Haven or Drone Patrol
Class 10 = (Faction) Sanctum or Drone Horde (hardest)

** Damage types ***
Guristas - Kinetic / Thermal (weak against
kinetic)
Serpentis - Thermal / Kinetic (weak against
thermal)
Blood Raider - Thermal / EM (weak against EM)
Sansha's Nation - EM / Thermal (weak against
EM)
Angel Cartel - Kinetic / Explosive / Thermal (weak
against explosive)
Mordus Legion - Thermal / Kinetic
Minmatar Fleet - Thermal / Explosive
Amarr Navy - EM / Thermal
Thukker Tribe - Thermal / Explosive