An 80% LTV means the borrower is putting 20% down (or has 20% equity on a refi). Below 80% LTV on conventional = no PMI required. Above 80% = PMI required until you hit 20% equity. FHA and VA have different insurance structures.
Jumbo programs often cap at 80–90% LTV. Non-QM programs sometimes extend to 85–90% on primary, lower on investment. DSCR typically caps at 80% purchase, 75% cash-out.
On a refinance, LTV is calculated from the current appraised value — so California property appreciation often moves you into a better LTV bracket even without paying down principal.