These are mandatory orders, but residents are allowed to leave their homes for essential needs, like buying groceries. People also don't need to carry paperwork on them to prove to officials that they can be outside.
Like lockdowns, each locale instituting a stay-at-home or shelter-in-place order can dictate specific restrictions.
These orders also typically spell the closure of nonessential businesses, like bars, nightclubs, and dine-in restaurants.
Curfews are not widely enforced yet in the US, though the Hawaii county of Kaua'i requires residents to stay inside from 9 p.m. to 5 a.m. South Fulton, Georgia is also requiring residents to stay in their homes between 9 p.m. and 7 a.m. except to perform essential services.
Fines or imprisonment could be issued if residents violate them, but officials can decide how strictly they will enforce.