What is a donor-advised fund (DAF), and what is its primary tax planning advantage?

A donor-advised fund allows you to make a large, irrevocable contribution of cash, securities, or other assets to a sponsoring organization (like Fidelity Charitable, Schwab Charitable, or a community foundation) and claim the full charitable deduction in that year. You can then recommend grants to qualifying charities over many years. This is particularly powerful for bunching multiple years of charitable deductions into a high-income year to exceed the standard deduction threshold, then distributing to charities gradually.