Most places called "Stan" believe in Islam, but not all of them, such as "Tuhorostan" (there was no Islam at that time). There is also "Hindustan" (written in Persian as hindustan). And "Stan" is by no means a political "country", and often it just refers to a general geographical area. For example, "Hindustan" sometimes refers to Hindi-speaking places in northern India, sometimes refers to the whole Indian subcontinent, or refers to India (there is a newspaper in India called Hindustan Times).
In a word, the meaning of "Stan" is generally nothing more than "region", "province (region)" and "country". In the past, it usually referred to a large geographical entity, which was rarely used by others. However, the situation is always changing. Over time, the name of the city also contains this ingredient. For example, there is a city in south-central Sakhak called Turkestan (in South Kazakhstan); In addition, there is a small town called Gulistan in Iran, Kazakhstan and Pakistan, but there are few such examples. Generally speaking, place names with "Stan" as the word-formation component have a long history. Such place names frequently appear in ancient Persian classics, and even have been repeatedly reflected in the chronicles of our country. But some of them are newly born, such as "Pakistan", which was born with the birth of a new country in 1947. It's only been half a century, and the rest can't be said to be ancient place names, such as the west coast of the Caspian Sea. Dagger Stan in the European part of the Russian Federation didn't have this name until17th century, but before that, it was never lightly read. As a generic name of place names, "Stan" is often combined with national names, so the meaning of place names is very obvious. Baluchistan means "Baluchistan region", Kurdistan means "Kurdish region" and so on. But not absolutely.