MwSt is the abbreviation for Mehrwertsteuer, which is also known as Umsatzsteuer (USt). This is the equivalent to VAT in the UK.
At present, MwSt is 19% for most items in Germany, with some items such as basic foodstuffs and books being only 7%. For some goods and services (eg. stamps) there is currently no MwSt.
The term “Mehrwertsteuer” was introduced in 1968, but the principles were first introduced as a form of stamp duty in 1916.
To hear a simple explanation and a short discussion in German, listen to the podcast:
(Press the “play” button to listen to the podcast)