noun which may take the genitive case particle 'no'
a certain; some kind of; of sorts
Used as a prenominal modifier to indicate that something belongs to a particular but unspecified type or category. Often implies a degree of vagueness or that the thing is hard to define precisely.
彼にはある種の魅力がある。
He has a certain kind of charm.
それはある種の誤解だ。
That's a misunderstanding of sorts.
ある種 means 'a certain kind of' and works like 一種の in figurative use, but 一種の feels a bit more compact and classification-like.
Standard kanji spelling.
Literary or formal variant using the kanji 或.
Compound of ある (a certain) and 種 (kind, type).