I have noticed already that there are a variety of different currencies, represented by various symbols which are all worth different values and used to purchase different things.
For example on some merchant windows I have noticed the following symbol 
for a currency called Karma, I've noticed the standard 
/ 
/ 
gold/silver/copper currency used as the generic base currency in many games, and something called 
gems which appears to be a pay to win currency in some form or other...
What are each of the currencies in Guild Wars 2, how do I earn them, and what is each currency for?
is the most common form of currency accepted by NPCs and is the basis for player
trade. It can be obtained via loot or as rewards for completing events
or completing achievements.
are used to purchase items from the in-game store; they can be exchanged or traded for coin.
is used to unlock skins for use in Structured PvP; it can only be obtained through participation in that
game mode.
can be spent on guild upgrades and boons; it is earned when players representing a guild participate
in events, PvP, personal storyline. A guild's accumulated influence
can be seen via the guild panel (G).
is used to purchase special items from designated NPCs; it cannot be traded and
must be earned by participating in dynamic events, helping others with
their personal storylines, or completing dungeons.
are used to unlock new skills and Miyani will take them in exchange for mystic items or
recipes.
is acquired through and used in WvW to build structure upgrades and siege weapons.
are earned by completing dungeons. Dungeon Merchants will accept them in exchange for items unique to
that dungeon.
