About half of all conventional home loans are called “conforming” loans, because they conform to guidelines established by Fannie Mae and Freddie Mac. These two government-sponsored enterprises (a.k.a. GSEs) buy loans from various lenders and sell them to investors on the open market. Their purpose is to make mortgages more widely available.
Loans that do not conform to Fannie or Freddie guidelines are referred to as “non-conforming” home loans. Non-conforming home loans that are larger than conventional home loan limits set by Fannie and Freddie and are often referred to as “Jumbo” mortgages.
Loans held by mortgage lenders on their own books are also called “portfolio” loans. Because lenders can set their own guidelines for these types of loans and do not sell them to investors, these products may have features that other mortgages do not.