Non-Compensating drippers are best for smaller systems with small to no elevation changes.

Non-Compensating means that this type of dripper does not "Compensate" for changes in pressure which can cause it to give higher output under higher pressure and lower output under lower pressure. For homeowners and small systems it should not matter but larger systems where the precise flow rates and ability to run as long as possible rows it is not a good choice. For those applications use a PC (Pressure Compensating) dripper.