Since the new Schengen Visa code came into effect from 2nd Febuary 2020, it is possible to acquire a multiple-entry Schengen Visa that can be valid for up to 5 years for certain citizens. With this visa you can travel to and from the Schengen Area as many times as you want. However, you cannot violate the 90/180 rule, which means that you can only remain in the Schengen Zone for 90 days in 180 days.