What are settlements, and why are they such a big deal?

Settlements are often described by observers of the conflict as creating new "facts on the ground." They change the situation by splitting Palestinian land and communities, while an increasing number of Israeli Jews put down roots in territory previously meant for Palestinians. So long as enough settlements are placed in the right places, a Palestinian state is geographically non-viable. For many settlers, this is the point: they want the West Bank fully incorporated as Israeli territory and are trying to make that happen. Any two-state solution will require demolishing a significant number of them…

https://www.vox.com/2018/11/20/18080052/israel-settlements-west-bank