How did 'equity' semantically shift to mean 'Assets — Liabilities'?
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 signify Assets — Liabilities?
What semantic notions underlie the emboldened abstract nouns overhead, with 'Assets — Liabilities'? I don't understand how " "equality, uniformity, conformity, symmetry; fairness, equal rights; kindness, moderation" appertains to 'Assets — Liabilities'. Please see the titled question.