To be more specific, hardscapes are generally anything that uses Rock, Brick, Pavers, Concrete, etc.
Some of the most common examples of hardscapes are retaining walls, Large rock steps going up or down a hill, flagstone walkways or patios, paver walkways or patios, concrete pathways or patios, Booulder accents in a landscape, gravel pathways, and brickwork of any kind as it relates to the landscape.