I think this is what you're wanting to know:
Stationary tills:
The money in a bar station or cashier station register would be a good example. The money in the drawer doesn't move around the site.
Floating-physical tills:
This would be a waiter who carries money on his person to make change directly for the customers at tables. Commonly known as "pursing".
Floating-virtual tills:
This would be a bunch of orders temporarily assigned to "delivery". The system may or may not track who drove the order to the customer, but it does track how many dollars were sent to the "delivery" module. This isn't a commonly used POS term - so don't feel bad if you haven't heard about it before.
Usually, virtual tills are implemented by software in casinos and cruise lines. Many times, the virtual tills are in fact change making machines - not people at all.