The Czech Republic Schengen Visa is a multiple-entry travel document to visit the Czech Republic and all the 27 countries of the Schengen Area. This visa is usually valid for a period of 180 days and you can stay in the Schengen Area for a maximum of 90 days per entry. We advise you to apply for this visa 2 months ahead to avoid any delays.
The Czech Republic is open to travelers from the EU and Schengen Zone countries without restrictions, so you shouldn't have to go through any additional measures. That said, it's important to check the entry rules from the country you are transiting through here before you book your flights as the rules can change suddenly.
It makes no difference whether this is 90 consecutive days in the Schengen area, or 90 days divided over 2 or more trips. See the following examples: If you have been in the Schengen area for 30 days within a 180-day period you can spend a maximum of 60 more days in the Netherlands or other Schengen countries within the same 180-day period. 4eSe.