Getting pre-qualified is the initial step in the mortgage process. Typically, pre-qualification can be done over the phone or on the internet and usually is free. You will provide basic information regarding your debt, income and assets. Loan pre-qualification is based only on the information you provide the lender and is not verified. Getting pre-qualified gives you an idea of how much you might be approved for, but is in no way guaranteed.
Getting pre-approved is the next step and will require that you complete a mortgage application. You will give your mortgage lender information on your income, assets and liabilities and they will pull your credit report. Getting pre-approved means that you are likely to be approved for a mortgage at the amount approved, but is not a guarantee.