Is the product a softener or a conditioner?
A water softener is defined here by what it does: it reduces calcium and magnesium hardness through cation exchange. “Water conditioner” is a broader, less precise marketing term. It can refer to a scale-control device, media treatment or even equipment a manufacturer also describes as a softener. The label alone cannot tell you the mechanism.
NSF/ANSI 44's technical scope covers residential cation-exchange softeners regenerated with sodium or potassium chloride. That supplies a useful reference point for identifying a true hardness-removing system.
Look for the physical process
A conventional softener has resin, a way to regenerate it with brine and a programmed regeneration sequence. A TAC conditioner uses a scale-conditioning medium without the same hardness-removal cycle. An electronic device may attach to a pipe and make a scale claim without a tank or regenerant.
Ask four direct questions: What is the medium or device? Where do calcium and magnesium go? Is regeneration required? What measurement will demonstrate the promised result? If the answer is that minerals remain in the water, the proposal should not promise the same hardness reduction as ion exchange.
There are technologies outside this site's residential cation-exchange focus that can remove hardness by other means. Avoid treating “salt-free” as a scientific guarantee that no hardness removal is possible anywhere; identify the actual device being sold for the home.
Match evidence to the promise
A hardness test is appropriate for confirming softening. It is not, by itself, a test of a conditioner that claims to retain minerals and change scale behavior. Conversely, a photograph of a cleaner fixture does not establish a quantified reduction in hardness.
Ask for the exact product's third-party testing, feed-water conditions, flow and evaluation method. A material-safety approval, lead-content certification or certified component does not prove every advertised scale claim. Read standards to separate the different types of evidence.
Assess ownership after you identify the class
A softener needs a salt supply, drain and applicable power; a particular conditioner can have different installation needs and media costs. “Maintenance-free” deserves the same specific questions as any other promise: are prefilters present, when is media replaced and what feed-water conditions could foul it?
Use types to investigate the identified class. Use salt-based versus salt-free when choosing between conventional softening and passive scale conditioning on cost and upkeep.
The useful comparison is a written outcome with a named mechanism and a suitable test. Require those three items before comparing brand names or prices. That prevents a terminology mismatch from becoming an expensive installation disappointment.