A lazy portfolio is any portfolio that requires a collection of investments with little maintenance. Basically, it is an easy set-up portfolio that you just let go and forget about it. You set it up and let it do its thing.
2-Fund Portfolio is one that is split with a Total World Index Fund and a Total Bond Index Fund. There will also be exposure to bonds that will help with any fluctuations within the market.
In this 3-Fund portfolio, Larimore breaks down the stock portion of the portfolio into two funds. One that follows the U.S. total stock market, and the other that follows the Total International stock market. He does this to give more exposure to the U.S. market in general.
A reit is a real estate investment trust. They are the big companies that like to own many different parts of real estate. There are REITs that own lots of shopping malls like Simon.