Batak is a collective term used to identify a number of ethnic groups found in North Sumatra; Indonesia. The term is used to include the Toba; Karo; Pakpak; Simalungun; Angkola and Mandailing; each of which are distinct but related groups with distinct; albeit related; languages and customs (adat). Occasionally it is also used to include the Alas people of Central/Southern Aceh; but usually only as relates to language groups. In North Sumatra; Toba people typically assert their identity as 'Batak'; while other 'Bataks' may explicitly reject that label; preferring instead to identify as specifically 'Simalungun'; 'Karo'; etc.