avatars - Virtual representation of an actual person.

SLURL - Tag used to locate a specific point on the Second Life grid.

virtual world - Immersive digital environment.

teleport - Moving from one virtual world to another or moving from one location within a virtual world to a different location.

pressence - The feeling of actually being inside a virtual world.

emocations - Gestures or key commands used to express emotion nonverbally.

bubble world - Type of virtual reality where a 360 degree environment is replicated through use of panoramic images. 

greifing - intentionally trying to harrass, annoy, or make things difficult for another avatar