This is the 149th most frequent Finnish word.
kyse
The Finnish word "kyse" means "concern, matter, issue, question, or query."
Here, 'kyseessä' is an idiomatic expression that means 'in question'. It introduces the topic being discussed.
Kyseessä on tärkeä kysymys.
It's an important question in question.
In this sentence, 'kyse on' is used to indicate what the topic or matter is, equivalent to 'It's about'.
Kyse on tiedosta eikä voimasta.
It's about knowledge, not power.
The phrase 'on kyse' is used in a question to inquire about the subject or matter in discussion.