It is an agreement, in principle, by the bank to offer you a home loan/financing, subject to confirmation of your personal details and credit status.
Online pre-approval saves time instead of going to the bank. You can apply for a loan/financing any time of the day. You can use this channel to find out how much you are eligible to borrow/obtain financing or if you can afford a particular property you are interested in purchasing, besides checking the status of your loan/financing from the time you apply until the loan/financing is disbursed.
You may not qualify for a loan/financing if the amount requested exceeds the limit which you are eligible for. In such an instance, you will be given a choice of amending the loan/financing amount and/or repayment period, or cancelling your loan/financing application.
You may use the 'Pre-approved Home Loan/Financing Enquiry' function any time after you have submitted your online application.