Appreciation means that the value of a product or investment rises. When the U.S. dollar's value goes up it has increased relative to currencies of other countries. Currencies trade in a 24/7 global marketplace, which means their values constantly change. Economic, political and financial activities and events can influence relative changes in the dollar's value.
A stronger dollar means U.S. companies have more buying power when purchasing goods in other countries. However, when they convert foreign currencies into U.S. dollars, they get fewer dollars than they would with a lower dollar value. For consumers and small businesses, a stronger dollar means more buying power in the local marketplace.