When the National Association of Realtors or Zillow quote homes sales statistics, they are often listed as various categories without explaining what the categories are or giving a definition of the category they are listing. So here are all the various categories and their definitions.
- Pending Home Sales. Tracks the sale of homes for which a contract has been signed but the sale has not yet closed escrow; that is, a contract has been signed by the seller & buyer, an escrow account has been opened to facilitate the sale, but the title has not yet transferred from the seller to the buyer (escrow has not closed).
- Existing Home Sales. The Existing-Home Sales data measures sales and prices of existing, already built, single-family homes for the nation overall that have already closed escrow; that is, the title has already transferred from the seller to the buyer. These figures include condos and co-ops, in addition to single-family homes. The data usually contains current sales rates, actual totals and median prices by month going back 12 months, annual totals for three years, and Includes all existing-home sales — single-family, condos and co-ops — rolled into monthly and annual totals.
You can find data for both of these at the National Association of Realtors website: http://www.realtor.org/research-and-statistics/housing-statistics
- Another category is New Home Sales. These are newly constructed homes that have closed escrow. Various sources compile data on new home sales and they are usually listed as monthly totals. Here are several sources:
http://www.tradingeconomics.com/united-states/new-home-sales
http://www.wsj.com/articles/u-s-new-home-sales-fell-7-6-in-august-1474898673
https://www.census.gov/construction/nrs/index.html
http://www.reuters.com/article/us-usa-economy-idUSKCN11W1KH
Another category that is also tracked by various sources is that of Building Permit Applications; that is, building permits applied for but houses not yet built. The Census Bureau tracks building permits:
http://www.census.gov/construction/bps/