and; or; connecting particle
A particle used to list two or more items or actions, implying that the list is not exhaustive.
や is used to connect nouns when you want to give examples from a larger set. It suggests there are other things not mentioned. For example, if you say 本やペン, you mean 'books, pens, and other things'. Unlike と, which lists everything, や leaves the list open. You can also use や with verbs, but in modern conversation it is more common to use たり or just connect with て. Using や with verbs is more typical in written or formal Japanese.