Central Asia is a region of Asia from the Caspian Sea in the west to central China in the east, and from southern Russia in the north to northern Pakistan in the south. It is also sometimes known as Middle Asia or Inner Asia, and is within the scope of the wider Eurasian continent. Various definitions of its exact composition exist and no one definition is universally accepted. Despite this uncertainty in defining borders, it does have some important overall characteristics. For one, Central Asia has historically been closely tied to its nomadic peoples and the Silk Road. As a result, it has acted as a crossroads for the movement of people, goods, and ideas between Europe, Western Asia, South Asia, and East Asia.

In modern context, Central Asia consists of the five former Soviet republics of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan. Other areas are often included such as Afghanistan, northeastern Iran and western parts of the People's Republic of China such as Xinjiang. Mongolia, Jammu and Kashmir, Northern Areas of Pakistan, southwestern and middle China such as Tibet, Qinghai, Gansu and Inner Mongolia, and southern parts of Siberia may also be included in Central Asia.

During pre-Islamic and early Islamic times, Central Asia was a predominantely Iranian region that included sedentary Sogdians, Chorasmians and semi-nomadic Scythians, Alans. The ancient sedentary population played an important role in the history of Central Asia. Tajiks, Pashtuns, Pamiris and other Iranian groups are still present in the region. After expansion by Turkic peoples, central Asia became also the homeland for many Turkic peoples, including the Uzbeks, Kazakhs, Kyrgyz and Uyghurs, and Central Asia is sometimes referred to as Turkestan.

Definitions

The idea of Central Asia as a distinct region of the world was introduced in 1843 by the geographer Alexander von Humboldt. The borders of Central Asia are subject to multiple definitions. Many text books still refer to this area as Turkestan, which was the name used prior to Stalin's rule.

The most limited definition was the official one of the Soviet Union that defined the "Middle Asia" as consisting solely of Uzbekistan, Turkmenistan, Tajikistan, and Kyrgyzstan, but did not include Kazakhstan, Afghanistan and Mongolia. This definition was also often used outside the USSR in this period. However, the Russian language has two distinct terms: Средняя Азия (Srednyaya Aziya or "Middle Asia", the narrower definition which includes only those traditionally non-Slavic, "Central Asian" lands that were incorporated within those borders of historical Russia) and Центральная Азия (Tsentral'naya Aziya or "Central Asia", the wider definition which includes "Central Asian" lands that have never been part of historical Russia). However, there lacks a meaningful distinction between the two in the English language; and so "Central Asia" is used for both Russian usages, thus creating some confusion.