"This section is here to familiarize yourself with common terms in the TWEWY universe. Don't understand the concept behind a word that someone mentioned in a post? Come here!"

http://twewy.wikia.com/wiki/The_World_Ends_with_You_Wiki
The TWEWY wikia is a good place to get information on Shibuya, Pins, Noise, and everything related to the Game in general.

Basic Terms:
These are common terms that most Players comprehend.

Player- A person participating in the Game.
Pact- An alliance between two Players. Necessary in order to play the Game. If one member of the pact becomes erased, the other will only have seven minutes to live unless they are able to form a new one or accept an offer to become a Reaper.
Scan- Using your player pin to read the thoughts of the pedestrians in Shibuya as well as search for Noise.
Noise- Creatures that are able to negatively influence the thoughts of people in the Realground and exist only to multiply and consume them. Created/summoned by Reapers. Take the form of anything from frogs to elephants.
Erasure- Ceasing to exist, literally being erased from existance
Underground ("UG")- The plane in which the Game takes place. Those existing in the UG are invisible to those in the RG.
Realground ("RG")- The living world.
Noise Plane- The plane between the UG and RG where Noise are fought.
Reaper- Help to run the Game and try to Erase/challenge players by using Noise. Erasure of Players lengthens their life span.
Game Master- Head Reaper of the week who gives the missions and is confrontable on Day 7.
Conductor- Second in command to the Composer.
Composer- The creator/overseer of the Game.

MAP