What is International Fisher Effect?

Legal Definition
The international Fisher effect (sometimes referred to as Fisher's open hypothesis) is a hypothesis in international finance that suggests differences in nominal interest rates reflect expected changes in the spot exchange rate between countries. The hypothesis specifically states that a spot exchange rate is expected to change equally in the opposite direction of the interest rate differential; thus, the currency of the country with the higher nominal interest rate is expected to depreciate against the currency of the country with the lower nominal interest rate, as higher nominal interest rates reflect an expectation of inflation.
-- Wikipedia