This is the 781st most frequent Arabic word.
بيروت
Beirut: The capital city of Lebanon.
In this sentence, 'بيروت' is used as a proper noun identifying the specific city that is the capital of Lebanon.
بيروت هي عاصمة لبنان.
Beirut is the capital of Lebanon.
Here, 'بيروت' functions as a geographic location where the action of working took place.
عملت في بيروت لمدة سنتين.
I worked in Beirut for two years.
'بيروت' in this sentence describes the market related to or located in Beirut, functioning as an associative term.