This is a definition that explains what a REIT is that can be used
in any communication or presentation:
A REIT, or Real Estate Investment Trust, is a company that owns, operates or finances income-producing real estate. Modeled after mutual funds, REITs give all investors access to the benefits of real estate investment along with the advantages of investing in publicly traded stock.
Note: For presentations and website definitions, not legal, a short version is often more appropriate than a longer, more technical definition.