Hi Andreas,
With the VM option, customers have the choice between 2 licensing options - a subscription option (which has support and maintenance included) or a Perpetual licenses option (which needs additional license for support or maintenance) which is typical of most pricing models. The choice really depends on whether a OPEX or a CAPEX model is desired for the purchase. Either methods provide access to the same capability just that in subscription you are subscribing for 1/3/5 years for the all encompassing service and in perpetual you buy the licenses outright and you own them and in addition (optionally) choose support for 1/3/5 years.
Hope that helps.