In getting a mortgage a variety of factors are considered during the calculation of your credit score such as:

how much money you earn.
how long you have been using credit.
whether you have made payments on time.
your level of education.
the number of years you have lived in a single location.
the number of years you have worked for the same employer.
whether or not you are a homeowner.

What the credit companies are looking for with many of these factors is your stability and your likelihood to repay the loan.