This term is often used by lenders and brokers. It simply means the ratio between the loan amount and the value of the property (without including the Mortgage Insurance premium)

LTV = Principal Loan Amount
Property Value

In general, the maximum loan-to-value (LTV) for a conventional mortgage is 80%.

For insured mortgages, the maximum LTV ratio is 95%.

Example: if someone is putting 5% down payment on a purchase of the property, their mortgage LTV = 95%