There are many different types of holocrons in SWG.
Collection Holocrons[]
Collection Holocrons can be looted from Force wielders NPCs on Dantooine and Nightsisters on Dathomir.
These collection pieces are very rare and can be worth a lot. The most common holocrons are the 3/5 pieces and are the least valuable of all. The rarest is the Strange Sith Holocron 4/5 (Waist Pack).
These holocrons grant you the Meditate ability and the Belt of Master Bodo Baas, a wearable item. You can complete these collections to activate another collection, the Master Jedi Cloaks, for the Cloak of Hate and the Shatterpoint Cloak.
Buff holocrons[]
There is a quest on Mustafar that grants you a Sith Holocron. It can be used once every hour to give you a 150 point increase in Constitution and Stamina.
Pre-nge holocrons[]
Pre-NGE Holocrons were hints at the class unlocks you needed to complete in order to unlock your Jedi slot. Players accessing holocrons would be told - quite directly - a class. In order to 'complete' that holocron, you needed to master that class. Once done, accessing another holocron would inform you of another class. These holocrons are nowadays used for nothing more than decoration.
Help system[]
This used to provide access to the online knowledge base system to contact cutomer support amongst other things. Now it has changed to the Help system which is an online non in-game system.
Star Wars Lore[]
- Holocron on Wookieepedia