Jumbo Loans are loans that exceed the conforming loan limits, and are not eligible to be purchased, securitized, or guaranteed by Fannie Mae or Freddie Mac.
As of 2019 a JUMBO is a loan of $484,851 or more in most areas. In high cost areas the starting point can be as high as $726,525 (varies depending on the County). If you're interested in finding out if your potential home is in a high cost ares, you can look at this Fannie Mae Loan Limit Table. Copy and paste address into new browser, https://www.fanniemae.com/content/tool/loan-limit-table.xls
JUMBO loans come in a variety of loan terms, FIXED rate, ARM's and INTEREST ONLY. Cash-Out, HELOC's (Home Equity Line of Credit) and rate and term refinances are available as well. Each type has it's own set of Qualification parameters.
Purchase transactions with Jumbo Loans require the home-buyer to put down a minimum of 10%-20%.
Most Jumbo loan programs allow you to purchase 1-4 unit Single Family, Condo's, PUD's and Co-ops. These can be financed with no prepayment penalty.