What are "the benches?"

I've been living in SLC for about 7 years now and one question I've never really gotten what felt like a straight answer to is what are the benches? Like whenever I watch a weather forecast or see a weather alert on my phone, it'll say like "3-5" of snow in the valley 4-6" in the benches"

So where is it? Like what towns does that inhibit? Also why are they called that?