Galactic Credits (what’s in a [credit]?)
While many planets in the universe have their own currenc[y/ies] that they use, the universe as a whole uses Galactic Credits as a basic form of currency. Galactic Credits are a currency used to help ease purchases so stores don’t have to have a price tag for every single currency in the galaxy.

[The symbol for the Galactic Credit; it’s an uppercase G with a C stylized to look like a planet’s ring attached to it.] ← This is the symbol used for Galactic Credits! If you see it around, now you know what it’s for!

Like it works here on Earth, different goods have different price points depending on where you are. A certain organization keeps track of these numbers, uses that to calculate the approximate worth of that currency, and works out the exchange rates so that the galactic economy remains functional and isn’t abused by others. Galactic Credits are something that they implemented to ease the exchange of those currencies between different planets.

Currency can be converted into Galactic Credits, which serve as a sort of “placeholder currency”, and Galactic Credits can in turn be converted back into other currencies!