Definition
A currency pair quotes the value of one currency, the base, in units of another currency, the quote currency, for a foreign-exchange transaction.
In market context
A move in the pair reflects the base currency strengthening or weakening relative to the quote currency, not an absolute change in either currency. Position direction, lot size, leverage, spread, financing, and account-currency conversion determine the resulting exposure and P&L. Foreign-exchange markets can move rapidly around economic releases or interventions, and retail off-exchange pricing may depend on the dealer.
Source
Use the primary source for fuller regulatory or market context.
