Kurdish is a dialect continuum

Dialect continuum

A dialect continuum, or dialect area, was defined by Leonard Bloomfield as a range of dialects spoken across some geographical area that differ only slightly between neighboring areas, but as one travels in any direction, these differences accumulate such that speakers from opposite ends of the...

 spoken by the Kurds in western Asia. It is part of the Iranian branch

Iranian languages

The Iranian languages form a subfamily of the Indo-Iranian languages which in turn is a subgroup of Indo-European language family. They have been and are spoken by Iranian peoples....

 of the Indo-Iranian

Indo-Iranian languages

The Indo-Iranian language group constitutes the easternmost extant branch of the Indo-European family of languages. It consists of three language groups: the Indo-Aryan, Iranian and Nuristani...

 group of Indo-European languages

Indo-European languages

The Indo-European languages are a family of several hundred related languages and dialects, including most major current languages of Europe, the Iranian plateau, and South Asia and also historically predominant in Anatolia...

.

The Kurdish language itself has about 16 million speakers today. According to KONDA, 11,97% of total population of Turkey knows Kurdish as their native or second language. According to the CIA World Factbook, 9% of total population of Iran speaks Kurdish. The actual number of ethnic Kurds is higher than speakers of Kurdish varieties, estimated to be between 25-30 million.

It exists in a continuum of dialects spoken in a geographical area spanning border regions of Turkey

Turkey

Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

, Iraq

Iraq

Iraq ; officially the Republic of Iraq is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....

, Iran

Iran

Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...

, Syria

Syria

Syria , officially the Syrian Arab Republic , is a country in Western Asia, bordering Lebanon and the Mediterranean Sea to the West, Turkey to the north, Iraq to the east, Jordan to the south, and Israel to the southwest....

, and a small number of speakers in the South Caucasus

South Caucasus

The South Caucasus is a geopolitical region located on the border of Eastern Europe and Southwest Asia also referred to as Transcaucasia, or The Trans-Caucasus...

.

There does not exist any single Kurdish language per se.