A coin is a tiny, often rounded, flat item that serves primarily as legal money or a means of exchange. They are mass-produced in a mint in order to simplify commerce, and their weight is standardised. Governments most frequently issue them. Coins frequently have pictures, numbers, or writing. The obverse and reverse of coins or medals, which relate to the front and rear sides, respectively, are frequently referred to as the faces. Because it frequently shows the head of an important person, the obverse of a coin is known as heads, while the reverse is known as tails.