A "REIT" is a real estate investment trust. REITs are companies that own -- and typically operate -- income-producing real estate or real estate related assets (i.e. mortgages). REITs are designed to be tax efficient: in order to qualify as a REIT, at least 90% of taxable income must be paid out to shareholders annually. For this reason, REITs typically offer attractive dividend yield, as well as long term capital appreciation as real estate values rise.