Both halves are landscaping. Almost nothing else about them is the same.
Hardscape
The half that's registered
Softscape
The half that isn't
The work
HardscapeRetaining walls, paving, decking, fencing, pergolas, water features. Anything that has to stand up on its own.
SoftscapeGarden design, planting, turf, mulching, ongoing maintenance. Anything that has to grow in.
What they type
Hardscape“retaining wall cost”. A number, before a name: they are pricing the job, not shortlisting you, and your own site has to answer “how much does a landscaper charge” and “how long do block retaining walls last” before the phone ever rings.
Softscape“backyard landscaping ideas”. A picture, before a price: they are shortlisting you, not pricing the job.
What it's worth
HardscapeThe top of your range. A backyard rebuild at $20,000 is two or three quotes deep before anyone rings.
SoftscapeThe bottom and the middle. A $2,000 tidy-up that turns into next spring's rebuild, if you stay in front of them.
The rules
HardscapeAbove $10,000 the job needs a major domestic building contract, and only a registered builder may enter one. Two named practitioner classes cover this work, and they are held by a person, not a business.
SoftscapeNone of that applies. Softscape builds no external structure, so it sits outside the scheme entirely, which is exactly why nobody writes about it honestly.
When it lands
HardscapeYear-round. Weather pushes a start date; it doesn't move the decision.
SoftscapeSeptember to November, and it isn't a preference. See below.