How the currency of a country is measured in term of other country's currency

Hi 1anurag1

On the basis of the value of the gold. The value of the gold has a International standard of value. And the basis of the value of the Gold in a particular country and the value of international value the value of the currency of a particular country is determined.

In my view, it depends on the supply and demand of these two currencies. Take rupee and dollar for example, if people need more rupees, they will exchange dollars for rupees, then rupee will rise in value. Why does exchange rate change frequently? I think the answer is that people make decisions according to the changing situations. For instance, if people are sure that investing in Indian stock market is profitable, they will exchange dollars they have for rupees, then the demand of rupees is increasing while the supplying of dollars is increasing. The outcome is that rupees appreciate against dollars.