Silesian (Upper Silesian) is spoken by the Silesian ethnic group (both Polish, Silesian and German nationalities) living in the region of Upper Silesia.
Silesian is spoken in the region of Silesia in south-western Poland and north-eastern Czech Republic and in several other places all around the world.
At present the Silesian is commonly spoken in the area between historical border of Silesia on the east, and line Sycow - Prudnik on the west, as well as in Rawicz area (Chazacy).
Cieszyn Silesia (Polish: Śląsk Cieszyński, Czech: Těšínské Slezsko, German: Teschener Schlesien) is a historical region in south-eastern Silesia, between the Vistula and Oder rivers.
The historical boundaries of the region are identical to those of the independent Duchy of Cieszyn.
The region is separated from the rest of Silesia (and Upper Silesia in particular) by Vistula river (the part beginning in Strumień neighbourhood), while from the region of Lesser Poland by Biała and Barania Góra mountain, the highest peak of the region (1220 metres a.s.l.