Yes sure the pass is valid on the vast majority of trains. Also valid on boats on Lake Thun and Brienz!

The only exception would be trains to peaks such as Jungfraujoch or Rigi. These are not included but you get a 25-50% discount:

https://benefitsportal.eurail.com/benefits/swiss-private-trains-benefits/

https://benefitsportal.eurail.com/benefits/swiss-private-boat-benefits/

Interrail in Switzerland is really cool as you remain flexible all along: seat reservations aren’t a thing. Simply log the train on Rail Planner app (before boarding), hop on and that’s it. :)

Now the question is Interrail One-country Switzerland vs Global Pass… what would you like to see in France? Is it far away from the border? If that’s the case a Global Pass is probably the best value.

Hi, thank you for your kind respond. I'll be travelling to nearby villages as daily trips from Switzerland. Like to Annecy or Colmar. Maybe a few more villages from Colmar than back again to Switzerland.

I guess a Global Pass should be good value then but you can always calculate separate tickets from the border (Basel - Colmar + Geneva/Annemasse - Annecy).

The number of pass days depends on you. If you're staying in the city the whole day it doesn't make to use a day and so on.

So to understand more precisely ( I haven't used any passes before sorry my asking) If I buy a flexi pass for seven days. Upon my arrival to Switzerland I can activate any time I like, let's say I activated my pass on the 2nd day of arrival. And I can use my pass for travelling to Colmar from Basel and also from Colmar to a few villages(Eguisheim and Riquewheir) and then back again to Basel. Also after that for travelling within Swiss for the consecutive days.  Am I correct? 

If you choose a 7 days within one month pass you can use the pass on any 7 days during a 30 day period (for example 28th April - 27th May).

They don't need to be continuous.

On the day you log the train on the app and it will deduct a pass day (there's a popup which you can't miss). No need to do that in advance, feel free to do that at the station (where you have wifi/data).

Within Switzerland I recommend using the SBB app for planning and anything transportation related.

If you get a Global Pass the train to Colmar is included. Note that there is no train station in either Eguisheim or Riquewihr so you'll have to buy a bus ticket separately.

Dear Thibcabe you have been most helpful. Please forgive my silliness of asking over and over again the same thing:). I am Turkish for my upcoming travel to Switzerland should I buy interrail pass or eurorail pass? And If I buy interrail pass; there is flexipass for 7 days which is suitable for my 8 day travel (4th-12th of may) or should I buy global pass? I couldn't figure out. 

If you’re living in Turkey, you need to buy the Interrail Pass. (The Eurail Pass is for non-European residents.)

You need to buy a Global Pass - that means it’s valid in all the countries. You can only travel in Turkey for two of your pass days.

Then you need to count how many days you will travel. That will help you decide which pass to get.

A Flexipass - like ‘7 days in 1 month’ means you can have 7 travel days, and all your travel has to be finished within a month. A Continuous Pass - like ‘15 days continuous’ means you can travel on all the days.

For you, the ‘7 days in 1 month’ sounds like the best one. As long as you won’t make any changes to your dates of travel. The ‘15 days continuous’ pass is nearly €100 more expensive, but could be useful if you change your plans and stay longer.