Turkey
Turkey geographically connects Europe and Asia. Its flag has a white crescent and five-pointed star directly on a red field.
After the collapse of the Ottoman Empire, the Republic of Turkey was proclaimed on 29 October 1923, under the leadership of Mustafa Kemal Atatürk. The republic celebrated its centenary in 2023.
Tunisia
The Tunisian flag puts a red crescent and red five-pointed star inside a white disk. So the circle is not the only difference from Turkey's flag: the crescent and star change color too.
Tunisia is a North African country on the Mediterranean coast. Its capital is Tunis; the country and capital have different names in English.

Related Flag: Red White and Black Flag, Green And Blue Flags