Base Currency

What Does Base Currency Mean?
The first currency quoted in a currency pair on forex. It is also typically considered the domestic currency or accounting currency. For accounting purposes, a firm may use the base currency to represent all profits and losses. 

 It is sometimes referred to as the "primary currency".

Investopedia explains Base Currency
For example, if you were looking at the CAD/USD currency pair, the Canadian dollar would be the base currency and the U.S. dollar would be the quote currency. The price represents how much of the quote currency is needed for you to get one unit of the base currency.