Home appraisals often get confused with home inspections — and while both play an important role in the homebuying process, they aren’t very similar.

During an inspection (which is optional), the property’s systems and structure are evaluated. The inspector will highlight deficiencies, safety hazards or repairs that may need to be addressed before you buy the home.

Appraisers, on the other hand, assess the value of a home to ensure your loan amount is appropriate. If you’re paying for the house with a mortgage, this process is mandatory.

Here are some other things to know about appraisals.

They’re done by a professional appraiser. Appraisals are conducted by professionals specifically trained in real estate valuation. A subset of appraisers have approval to appraise properties for FHA and other government loans.

Physical assessments aren’t always included. Some appraisals are done via an in-person physical evaluation of the house. There are also drive-by appraisals based on the home’s exterior and desktop appraisals, which are data-based — using property records and local sales data to determine value.