PMI is a type of mortgage insurance. It is typically required on a conventional loan if the down payment is less than 20% of the home’s purchase price.
PMI may also be required to refinance if your equity is less than 20% of the value of your home.
Equity is the amount you have paid toward the loan principal through the down payment, your monthly payments, and additional payments to principal. Increases to your house’s market value can also increase your equity.