Singapore regulates chauffeured transport as private hire, a category distinct from taxis. The vehicle is licensed for hire, the driver holds a vocational licence issued by the Land Transport Authority specifically for private hire work, and the journey must be booked rather than flagged down. Taxis hold a different vocational licence, may be hailed on the street and take passengers from ranks. Private hire cars may do neither.
Both categories are tightly regulated and both are reliable, which makes this an unusually honest market to write about. The practical difference is what happens around the edges of a journey: a booking made in advance carries a fixed price with no airport, peak or midnight surcharge, a named chauffeur assigned before you land, a vehicle class you selected, child seats fitted before arrival, and an hour of waiting that costs nothing when your flight is late.