What is mortgage insurance?

Mortgaging one’s house for a loan is a major and long-term commitment. Mortgage payments typically continue over several years, and one can never predict fluctuations in the borrower’s ability to repay at the moment of taking out a mortgage. Hence, the borrower may have to purchase mortgage insurance to protect against the risk of future non-payment of dues because of financial difficulties due to sickness, disability or unemployment. 
http://www.myallagents.com/What-is-mortgage-insurance/details.html.