ETIAS
ETIAS travel authorisation is an entry requirement for visa-exempt nationals travelling to a Schengen country. It is linked to a traveller’s passport. It is valid for up to three years or until the passport expires, whichever comes first. If you get a new passport, you need to get a new ETIAS travel authorisation.
With a valid ETIAS travel authorisation, you can enter the territory of these European countries as often as you want for short-term stays - normally for up to 90 days in any 180-day period. However, it does not guarantee entry. When you arrive, a border guard will ask to see your passport and other documents and verify that you meet the entry conditions.
Countries of which citizens are authorized to get ETIAS.
For more infomration visit official web site of ETIAS.