A real estate appraisal is a service performed by a licensed or certified appraiser, who develops an opinion of value based upon the highest and best use of real property. The highest and best use is that use which produces the highest value for the land, as if vacant. This use is based on 4 parts; physically possible, appropriate, legal, and economically feasible. Also of importance is the definition of the type of value being developed and this must be included in the appraisal, i.e. market value, condemnation value, quick sale value, etc. For mortgage valuations of improved residential property, this value is most often reported on a standardized form, the Uniform Residential Appraisal Report.

An appraisal is performed for a specific client, to whom the appraiser has a fiduciary responsibility, regardless of what party ultimately pays for the appraisal, whether anyone actually pays for the appraisal, or when the appraisal is paid for. Typically residential appraisers agree to accept orders from lending institutions with the understanding that payment will be made following settlement, or closing of the loan. In most cases, the homeowner or buyer ultimately pays for a residential appraisal, either directly or rolled into settlement fees.