WHAT IS THE ISLAMIC DINAR AND DIRHAM?

According to Islamic Law...
The Islamic Dinar is a specific weight of gold equivalent to 4.3
grammes.
The Islamic Dirham is a specific weight of silver equivalent to
3.0 grammes.

Umar Ibn al-Khattab established the known standard relationship
between them based on their weights: "7 dinars must be
equivalent to 10 dirhams.

"How can I use them?
1.- I can save them because they are wealth in themselves.
2.- I can pay zakat and dowry as they are requisite within Islamic
Law.
3.- I can buy and sell with them since they are a legitimate
medium of exchange.