This is the 392nd most frequent Japanese word.
券
Ticket; coupon; certificate.
In this context, '券' represents a voucher or coupon that provides a discount or special offer.
レストランで割引券を使いました。
I used a discount coupon at the restaurant.
In this case, '券' denotes a voucher or gift certificate that can be exchanged for books.
図書館で図書券が当たりました。
I won a book voucher at the library.
Here, '券' refers to a physical ticket used for entering a venue, specifically a movie theater.