@Stahesh Inflation rate is a measure of how fast prices go up or down. While companies decide the price of their products and services, it usually reacts to market conditions.
However the bulk of the inflation in Western countries comes from government spending habits: if taxes aren't enough, they will print additional currency to make up for lack of budget. Once the gov spends that money, it hits the market at once with more money supply and at a fixed demand, hence the devaluation.