“PIP” stands for Point In Percentage. More simply though, a pip is what we in the FX would consider a “point” for calculating profits and losses.
When trading a mini lot (10k units of currency), each pip is worth roughly one unit of the currency in which your account is denominated. If your account is denominated in USD, for example, each pip (depending on the currency pair) is worth about $1.
In all pairs involving the Japanese Yen (JPY), a pip is the 1/100th place — 2 places to the right of the decimal. In all other currency pairs, a pip is the 1/10,000 the place — 4 places to the right of the decimal.