On the northern side of the Strait of Hormuz, indisputably, lies Iran. But which country is on the southern side?
If asking this as a quiz question, you should probably be prepared to accept "the United Arab Emirates" (or " the UAE") as a correct answer, as well as "Oman".
Across the strait from Iran (i.e. on the southern side) is a sharply pointed peninsula. The very tip of this peninsula belongs to Oman, but this is an exclave. Most of the peninsula belongs to the UAE, which has a coastline on either side (west and east) of the peninsula.
If you travel eastwards through the Strait of Hormuz, you very quickly come to the Gulf of Oman. Once you get there, the UAE is behind you (or astern, if you prefer) and the coastline on your right (starboard) is Oman.
If you need a map to make all this clear (and I wouldn't blame you if you did), this article on a US Government website has one that should help.
© Haydn Thompson 2020