Pre-qualification is generally a quick, initial check that lenders perform to give you an idea of the loan amounts and terms you might qualify for, based on a soft inquiry of your credit report (which doesn't affect your credit score). Pre-approval is a more in-depth process that typically involves a hard credit check (which may impact your credit score) and provides a more concrete loan offer. Pre-approval indicates the lender has reviewed your credit, income, and other factors, and is conditionally willing to lend you a specific amount under certain terms.