Mehrwertsteuer
... German for Sales tax (externer Link)
Sales tax means: Tax paid when bying an item. If, for example, a shopkeeper wants to sell a bike for 600 Euros the state says: Add 20 % to that price and give me those 20 %. The shopkeeper would then have to sell his bike for 720 Euro (20 % added). The original 600 Euros he can keep to himself. The 120 Euros are the sales tax. The shopkeeper has to give those 120 Euro the the state.
When tracked through a whole supply chain, the sales tax is handled as a so-called VAT (value-added tax).