Refers to the quality of being soft, tender, or gentle, whether physically (texture, pliability) or abstractly (gentleness of character, light, etc.).
このパンの柔らかさが好きです。
I like the softness of this bread.
彼の声の柔らかさに癒やされた。
I was soothed by the tenderness of his voice.
硬さ describes hardness or firmness, while 柔らかさ describes softness or pliability, the direct physical opposite.
Standard kanji spelling for softness or tenderness in a general sense.
Alternate kanji spelling; 軟 often implies physical pliability or flexibility, but both forms are used.
Noun form of the adjective 柔らかい (やわらかい, 'soft'), derived from the stem 柔らか- plus the nominalizing suffix さ (-sa), which turns adjectives into nouns expressing degree or quality.