Both currency depreciation and currency devaluation end up with a currency that is worth less than it previously was in comparison to the currencies of other countries. The difference is in how the currency comes to be worth less.
Depreciation occurs only in
countries that allow their exchange rates to float. That is, these
countries allow supply and demand to determine the value of their currency
relative to the currencies of other countries. Depreciation occurs when
the forces of supply and demand cause the value of their currency to
drop.
By contrast, devaluation occurs
only in countries that do not allow their exchange rates to float. These
countries’ governments control the official value of their currency. They
typically use government money to buy or sell currency so as to keep the
exchange rate where the government wants it to be. Devaluation occurs
when a government decides that it needs to have its currency be worth
less. It then allows its currency to become weaker.
In general, depreciation is
considered to be a better thing because it happens “naturally” where
devaluation is artificial.
devaluation is taking the exchange
rate from equilibrium to a disequilibrium situation; fix the exchange rate
below its equilibrium value; create a situation where demand for the currency
exceeds supply of the currency.
However, depreciation implies a lower
equilibrium exchange rate following an increase in supply of the currency or a
decrease in the demand of the currency.
depreciation and appreciation is for
floating exchange rate
and devaluation and revaluation is only for fixed exchange rate
hope that helps.