It is a simple belt with steps or platforms and handholds rather than an elevator with cars.
The belt moves continuously, so one can simply get on when a step passes and step off when passing any desired floor without having to call and wait for a car to arrive.
[1] Although not technically a paternoster, it has many of the same design features and hazards associated with its use.
[2][3] They are used in grain elevators and parking garages where space is limited.
In Canada, manlifts were retrofitted in the early 1990s with safety features after fatal accidents.