It's the difference between devaluing and inflation.
devalue
(diˈvæl yu)
v. -valued, -valuing. v.t.1. to set a lower exchange value on (a currency).in·fla·tion
inˈflāSH(ə)n/nounnoun: inflation Economicsa general increase in prices and fall in the purchasing value of money."policies aimed at controlling inflation"
We hear pundits and posters confuse these terms a lot.
the way I view this
inflation=cause
devalue=effect