I confused about Swiss pass and Interrail pass....

Hello miki. Based on your information, it's hard to say which option is best. Generally, I'd say an 8 day Swiss (Youth) Pass is best if further traveling outside of Switzerland is limited to a few trips such as Switzerland-Paris and Paris-Amsterdam. If more intensive traveling in these countries is involved, a Eurail or Interrail Pass might be more convenient. But you'll only know for sure if you make your plans as detailed as possible and do the math as explained here. Please carefully compare all details of the Swiss Pass, Eurail Passes and the Interrail Pass.

Here are some things to consider:

• I'm not sure whether you're eligible for Interrail Passes. They're meant for residents of Europe, so you should possess a Danish passport or a permit;
• if you can't use an Interrail pass but do intend to buy a pass that's valid for more countries, you should look into Eurail Passes instead. Most of them come in 1st class only though;
• if you plan to take the Glacier Express to travel from Lausanne to Chur, note that it would be for free with a Swiss Pass, but partly discounted with a Eurail Pass. This might make an important difference;
• if you're under 26, you can get an 8 day 2nd class Swiss Youth Pass. That would be the cheapest solution of all Swiss Pass variants.