What is a volume?

The volume represents the number of shares which were traded during a predefined time span usually one day. This amount of shares which have exchanged hands between the buyer and a seller, for example if the buyer has sold 1.000 shares then the volume has increased by 1.000. The volume represents a really important number for analysts, and by this number they can estimate how much has worth the market move. It is considered that the higher the volume during a move then more significant it has been the move it self.