Percentage in Point or Price Interest Point
A pip is the smallest price move that a given exchange rate makes based on market convention. Since most major currency pairs are priced to four decimal places, the smallest change is that of the last decimal point; for most pairs, this is the equivalent of 1/100 of 1%, or one
basis point. For example, the smallest move the USD/CAD currency pair usually makes is $0.0001, or one basis point.
Read more: Pip Definition | Investopedia
https://www.investopedia.com/terms/p/pip.asp
A pip is sometimes confused with the smallest unit of change in a quote, i.e. the
tick size. Currency pairs are often quoted to four decimal places, but the tick size in a given market may be, for example, 5 pips or 1/2 pip.
Source:
https://en.wikipedia.org/wiki/Percentage_in_point
Yen-based currency pairs are an exception and are displayed to only two decimal places (0.01).
Some brokers now offer
fractional pips to provide an extra digit of precision when quoting exchange rates for certain currency pairs.
Source:
https://www.oanda.com/forex-trading/learn/intro-to-currency-trading/conventions/pips