This may have been explained somewhere but I have not found it yet. What is Uber?
Uber calls itself a "ride share" service, but in reality it's an alternative taxi service. It is only accessible via their app on a smart phone or tablet. Uber drivers are independent contractors driving their own cars. Uber accepts ride requests via the app, and dispatches a nearby driver (taking a big chunk of the fare for their trouble.) Payment is via a credit card or PayPal registered on the app; cash is not accepted. Uber does not handle or encourage tipping; drivers of course welcome tips, but tips must be in cash paid directly to the driver. At the end of a trip, drivers rate the passengers, and passengers rate the driver on the app; either can be banned from the service due to consistently low ratings.
In some areas (MCO), Uber offers Uber Black and Uber SUV, which use the same model but dispatch licensed professional drivers in limos instead of ordinary drivers.
Lyft is a competitor of Uber with a similar operating model, but does encourage and accept tips. Lyft seems to be a little more selective about accepting drivers, and tries to cultivate a fun atmosphere, whereas Uber is pretty much all business. Which is not to say Uber drivers are not friendly and helpful, but Lyft, for example, has been known to put pink mustaches on it's drivers' cars.
Both Uber and Lyft circulate promo codes that can reduce a big chunk of your fare. Uber riders and drivers may give promo codes to prospective new riders that get the first ride free, up to a certain amount. Lyft is currently offering $5 off each of the first 10 rides in the Orlando area.