This is the 6754th most frequent Russian word.
suisse
The word "suisse" is not Russian; it's French for "Swiss" (relating to Switzerland).
Here, 'Швейцарии' is used in the ablative/genitive case to specify origin.
Я встретил туриста из Швейцарии.
I met a tourist from Switzerland.
In this sentence, 'Швейцарии' is used in the prepositional case to denote location.
Он сказал, что жить в Швейцарии очень приятно.
He said that living in Switzerland is very pleasant.
In this sentence, 'Швейцарии' is the genitive form of the word 'Швейцария', which translates to 'Switzerland'. This denotes possession or relationship.