"알타이계" refers to a proposed language family that includes several languages spoken in Central and Northern Asia. This family is thought to encompass languages such as 터키어, 몽골어, and 우랄어. Linguists suggest that these languages share common roots and features, indicating a historical connection among them. The term "알타이계" is derived from the 알타이 산맥, a region in Central Asia where many of these languages are spoken. While the classification of these languages into a single family is debated, the concept highlights the cultural and linguistic diversity of the area.