Istan is a Persian word that means "land." Seven countries in the world end with "-istan" or "-stan" or How many countries end with 'stan': Afghanistan, Kazakhstan, Kyrgyzstan, Pakistan, Tajikistan, Turkmenistan, and Uzbekistan. Similarly, in English, many countries end with the suffix "-land" (England, Finland, Greenland, Iceland, and Ireland, for example).
"Afghanistan" means "land of the Afghans," Uzbekistan means "land of the Uzbeks," and Pakistan means "land of the pure."
Bonus Explainer: Does the city of Istanbul derive its name from the same root? No. Most sources think "Istanbul" comes from the Greek phrase stin poli, meaning "to the city."
"Stan" in several Middle and Near Eastern languages means "land," so "Afghanistan" simply means "Land of the Afghans," "Uzbekistan" translates as "Land of the Uzbeks," and so on. "Pakistan" is a bit fancier, meaning "Land of the Pure." According to the Slate article, there are seven countries ending in "istan" or "stan": Afghanistan, Kazakhstan, Kyrgyzstan, Pakistan, Tajikistan, Turkmenistan, and Uzbekistan. I happen to know of one other region ending in "stan" not mentioned in the article, Tatarstan in the Russian Federation, and there may well be others.
I was told that the word 'stan' means 'Land' as all mentions, and it's from old Persian language. I was also told that it is related to such words like Stadt, Stat (meanintg Town) in many Indo-Europ. languages and 'state' or 'estate' in English