Pip refers to point in percentage. However more simply, a pip is what we in Forex would check a point for computing P&L.
If you are trading in mini (i.e. 10,000 units of currency), one pip refers to the one unit of currency in which the account is denominated. If the account is denominate in US dollars, then each pip (depending on currency pair) is value of about $1.
In all the involving Yen, a pip is (1/100)th place i.e. two place on the right of the decimal. However, in all the other currencies, a pip is (1/10000)th place i.e. four place on the right of the decimal.