I read that they will cooperate with banks? Is this really so?
Yes this is true!
They plan to build their system in such a way that it works with partner banks

And which ones will they cooperate with banks?
Which options will be available?
They conclude partnership agreements with many banks, this will allow the transfer of money between the networks quickly and without any commission.
But in which way?
And which currencies can be used for this?
Well, I do not think there will be any restrictions on currencies.
That is, it will be possible to exchange any currency units

I understand this, but how does it work?

I do not know the details, but I can assume that the currency is simply converted into a token, and transferred to another user with further conversion.
But I can not know the details of the implementation, these are just my assumptions

Well, I hope we'll find out after the crowdsale.