noun
admission ticket; entrance ticket
General ticket for entering a venue, event, or facility.
コンサートの入場券を2枚買った。
I bought two admission tickets for the concert.
noun
platform ticket
Specifically a ticket for entering a railway station platform without traveling; common at Japanese stations.
見送りのために入場券を買ってホームに入った。
I bought a platform ticket to see someone off and entered the platform.