I ask about Equity = Assets — Liabilities here, not its meaning as stock. See Personal Finance For Canadians For Dummies (2018). p 468.
equity: In the real-estate world, this term refers to the difference between the market value of your home and what you owe on it. For example, if your home is worth $400,000, and you have an outstanding mortgage of $150,000, your equity is $250,000. Equity is also a synonym for stock.
early 14c., "quality of being equal or fair, impartiality in dealing with others," from Old French equite (13c.),
from Latin aequitatem (nominative aequitas) "equality, uniformity, conformity, symmetry; fairness, equal rights; kindness, moderation,"
from aequus "even, just, equal" (see equal (adj.)).
As the name of a system of law, 1590s, from Roman naturalis aequitas, the general principles of justice which corrected or supplemented the legal codes.
Why was 'equity' was adopted to describe this difference?
What semantic notions underlie the emboldened abstract nouns overhead, with 'Assets — Liabilities'? Please see the titled question.