QBO International - Unrealized Gain/Loss

It appears that “Unrealized Gain or Loss” is a QBO background function account, but the “Exchange Gain or Loss” account appears to be a normal account.  Why do we have the option to show the unrealized gain/loss? I am confused about the entire concept.

• Unrealized Gain or Loss
• What is the purpose of this account?
• I am unable to change the name of this account, why?
• How do you realize the gain or loss?
• Per US GAAP, unrealized gains or losses should be recorded in the equity section of the Balance Sheet. Why is currently on the Income Statement?

• Exchange Gain or Loss
• What is the purpose of this account?
• Is this where the gain/loss on currency revaluation goes?
• We perform revaluing currency at month end, correct?