What closing costs actually are
Closing costs are the settlement expenses that come with finalizing a mortgage. They fall into a few broad groups: lender fees for originating and processing the loan, third-party costs such as title work and the appraisal, and prepaid items like the first portion of your property taxes and homeowners insurance that get collected up front.
They are separate from your down payment, and they vary from one loan to the next. Some are fixed, some scale with the loan amount, and some are simply pass-throughs from third parties.