As the term implies, these loans "bridge the gap" between times when financing is needed. They are used by both corporations and individuals and can be customized for many different situations. For example, let's say that a company is doing a round of equity financing that is expecting to close in six months. A bridge loan could be used to secure working capital until the round of funding goes through. For an individual, bridge loans are common in the real estate market. As there can often be a time lag between the sale of one property and the purchase of another, a bridge loan allows a homeowner some flexibility.
A wrap-around is attractive to lenders because they can leverage a lower interest rate on the existing mortgage into a higher yield for themselves. Usually, but not always, the lender is the seller. In general, only assumable loans are wrappable.