RO — Reverse Osmosis
RO uses a membrane and pressure to separate a range of dissolved substances. Performance depends on membrane condition, pressure, source water and system design.
UV — Ultraviolet
UV is used as a disinfection stage when correctly sized, powered and maintained. It does not function as a sediment or dissolved-solid filter.
UF — Ultrafiltration
UF uses a membrane with larger pores than RO. It can support particle and microorganism control but does not provide the same dissolved-solids separation as RO.
Carbon and sediment stages
Sediment and activated-carbon components protect later stages and help manage visible particles, taste, odour and chlorine where relevant.
Why combined systems exist
A multi-stage unit combines complementary jobs. The useful question is not which acronym sounds strongest, but which configuration suits the actual source and maintenance plan.