Comparable properties are used to determine the proper estimated value of a home about to be placed on the market.  “Comps” do not need to be identical to the subject in physical characteristics or location, but should include some similar characteristics. In addition, the highest and best use, land-to-building ratio, terms of the sale and the market conditions should be similar or relatively easy to adjust for comparison. 

To summarize, the more recent the sale and the fewer the dissimilarities to the subject property, the better the comparable will assist in determining the asking price of the home under evaluation.