For how long and how often can I travel?
Each Eurail Pass is available with different numbers of travel days.
All Passes have the flexi pass option: you have a fixed number of travel days which you can use whenever you want during the overall period that your Pass is valid, such as 15 days within 2 months.
The Eurail Global Pass also has a continuous pass option: you may travel on as many trains as you want during the entire period that your Pass is valid, such as 15 days continuous travel.
The number of travel days and the period of validity varies between each Pass and country. You can also use a second Eurail Pass after your first finishes.