The appraisal is the process of developing and communicating an opinion about a property’s value.  The appraisal is conducted by a licensed professional typically working for the lender.  It usually includes comparable market information or direct sales comparison, reproduction or replacement cost estimates and, if applicable, the income approach which considers capitalization of net operating income from a property.

A comparable market analysis (CMA) is estimation of a property's value is based on the recent sale prices of properties within the same area that are comparable in square footage, amenities and features similar as well as information regarding comparable active properties (for sale on the market) and expired properties (where the assumption is that they failed to sell for being overpriced.)

The Zestimate - Zillow’s home valuation approach - is computed using a proprietary formula and historic sales and local authority data. It often does not include changes, upgrades or local nuances unique to the property and can therefore only be seen as a starting point in determining a home's value or a broad range of value.