In this video, Mortgage Loan Officer Conroy Jackson defines both formal approval letter and credit approval letter/pre-qualification. 
A formal approval letter is notification that the lender has conditionally approved an applicant’s request for a loan.
Having a credit approval letter/pre-qualification from a reputable lender can increase your chances of having your offer on a home accepted. Learn more about credit approval with Mortgage Loan Officer Conroy Jackson (NMLS ID 185902). 

Cambridge Savings Bank – Member FDIC – Equal Housing Lender – NMLS ID 543370