Hillary and Bill Clinton address the audience during the opening of a Clinton Global Initiative event in September 2014 in New York City. (Michael Loccisano/Getty Images)

In recent weeks, the presidential campaign has been dominated by stories about the charitable efforts — or lack thereof — of Donald Trump and Hillary Clinton.

So what do we know about Trump’s and Clinton’s approaches to charity — and about the charitable foundations that share their names?

1. First: Didn’t Trump say that he gave money to Clinton’s foundation, so that Clinton would attend his third wedding?

Yes. He did say that.

Washington Post reporter David Fahrenthold is investigating how much Republican presidential candidate Donald Trump has given to charity over the past seven years. Here's what he found. (Sarah Parnass/The Washington Post)

“I said, ‘Be at my wedding,’ and she came to my wedding,” Trump said in a Republican primary debate in August. “You know why? She didn’t have a choice because I gave. I gave to a foundation that, frankly, that foundation is supposed to do good.’

2. Is that true?

Only in part.

Trump has never actually given any of his own money to the Democratic nominee’s famous family charity, the Bill, Hillary and Chelsea Clinton Foundation.

Trump did, however, send two gifts from a foundation he controls, the Donald J. Trump Foundation.

In 2009, the Trump Foundation sent a $100,000 “unrestricted gift” to Clinton’s charity. In 2010, Trump’s foundation sent $10,000, to reserve a table at a Clinton Foundation gala. Trump did not actually attend.

But it’s a stretch for Trump to imply that he actually gave this money personally. By 2009, only a tiny fraction of the money in the Donald J. Trump Foundation had been given by Trump. (More on that later.)

And Trump is wrong to suggest that these gifts to Clinton’s foundation came before Clinton’s decision to attend his wedding.

The gifts were in 2009 and 2010.

The wedding was in 2005.

3. Step back. How much money have Clinton and Trump each donated to charity?

For Hillary and Bill Clinton, the total is $23.2 million between 2001 and 2015. That figure comes from the Clintons’ joint tax returns, which the Democratic nominee has released.

In that 15-year period — the years since the Clintons left the White House — they earned about $237 million in adjusted gross income, much of it from speaking fees and book royalties. So Clinton and her husband donated about 9.8 percent of their adjusted gross income.

Trump says he is worth far more than the Clintons. He recently claimed his net worth as more than $10 billion.

But it appears he has donated far less.

The Washington Post has identified about $3.9 million in donations since 2001 from Trump’s own pocket.

The most recent of those donations was made Wednesday, to a church in Louisiana that Trump had visited during a tour of flood-ravaged areas the week before. Trump sent a personal check for $100,000 to Greenwell Springs Baptist Church, whose interim pastor is a well-known social-conservative activist, Tony Perkins.

(Louisiana’s Democratic governor had suggested before Trump’s visit that the candidate should give to a specific relief fund, run by the Baton Rouge Area Foundation. Trump gave nothing to that fund.)

Before that, there was a $1 million gift that Trump made in May to the Marine Corps-Law Enforcement Foundation. At the time of the gift, Trump was under media pressure to make good on a promise he’d made four months earlier: to give $1 million to help veterans.

Beyond that, the evidence of Trump’s giving comes from the files of the Donald J. Trump Foundation, which the businessman founded in the late 1980s. Since 2001, those files show about $2.8 million in gifts from Trump himself.

But they also show that Trump’s giving to his foundation declined sharply a decade ago.

Then it stopped completely.

In the foundation’s tax records, the last donation shown from Trump was in 2008, for $30,000. Since then, other donors have filled the Trump Foundation’s coffers instead: Since the start of 2007, Trump has provided just 0.73 percent of all the money donated to the foundation.

Has Trump made any other recent donations, beyond the gifts to the veterans’ group and his own foundation?

His staff says he has.

But they have provided no dollar figures and no proof. Trump has also declined to release his tax returns, unlike every other major-party nominee for four decades.

The Washington Post has spent months searching for evidence of other personal gifts from Trump and found little. After calling more than 270 charities with ties to Trump, The Post has identified just one other personal donation since 2008.

That was a gift of less than $10,000 in 2009, to the Police Athletic League of New York.

There is a chance it is a clerical error.

4. When the two candidates did give, what charities did they choose?

The Clintons give nearly all their money away via a charity called the Clinton Family Foundation.

It is basically a pass-through, of a kind commonly used for charity by many wealthy people. It does no direct charitable work but passes money to other nonprofit organizations.

In all, the Clinton Family Foundation gave away $18.4 million of the Clintons’ money between 2001 and 2014, the most recent year for which the group’s tax returns are available. Those donations include grants to many groups based in Arkansas, where Bill Clinton served as governor, and Chappaqua, N.Y., where the Clintons moved after leaving the White House. Among them: the Chappaqua Volunteer Ambulance Corps, Immanuel Baptist Church in Little Rock, the Arkansas Community Foundation and the University of Arkansas. They also made donations to major national charities such as the Elizabeth Glaser Pediatric AIDS Foundation.

The largest single recipient of money from the Clinton Family Foundation was the family’s other, far more complicated charity.

That’s the one you’ve heard of: the Bill, Hillary and Chelsea Clinton Foundation.

The Clintons have given $4.3 million of their own money to it since 2001, representing 24 percent of their personal giving in that time. More on that other Clinton foundation in a moment.

In Trump’s case, the businessman still controls where the Donald J. Trump Foundation spends its money — even if he doesn’t provide that money from his own pocket anymore.

And tax records show that, under Trump’s leadership, the foundation’s giving has been relatively small-bore and scattershot. There are some repeated patterns: a number of donations to veterans’ groups, police department foundations and New York-area hospitals.

But it lacks the sustained commitments to specific institutions and causes that many wealthy people adopt in their giving.

In many cases, the Trump Foundation’s donations appear to have been spurred by one-off encounters in Trump’s own life.

For instance, the fifth-biggest donation in the Trump Foundation’s recent history — $158,000, in 2012 — seems to have been used to settle a lawsuit against one of Trump’s golf courses. A man named Martin Greenberg had sued, claiming a mistake at the course cost him a huge hole-in-one prize. On the day the parties told a court their suit was settled, Trump’s foundation sent Greenberg’s foundation a check.

Trump’s foundation also donated to at least 15 charities connected to “The Celebrity Apprentice,” the reality show where contestants played to help a cause. On the show, Trump would often promise a special donation “from my own wallet” — but then, when cameras were off, send a donation from his foundation or from a production company.

And, in another case, Trump used the charity’s money to purchase a football helmet signed by then-Denver Broncos quarterback Tim Tebow. That $12,000 purchase, at a charity auction, might have violated IRS rules — which prohibit a charity’s leaders from using nonprofit money to buy gifts for themselves.

5. Wait, go back. There are two Clinton foundations?

Yes. Two.

The Clinton Family Foundation is a nonprofit used by Bill and Hillary Clinton for their personal charitable giving. The Clintons are its only donors.

But the Clinton charity in the news this week is the other, bigger one — the Bill, Hillary and Chelsea Clinton Foundation.

That one was founded by Bill Clinton in 1997, while he was still president and was originally known as the William J. Clinton Foundation. Initially, the foundation’s goal was to raise money for the construction of Clinton’s presidential library. After he left office, however, the foundation’s goals and funding expanded rapidly. It soon became the chief vehicle for Bill Clinton’s post-presidential ambitions, a way to help charities and promote his own celebrity worldwide.

The foundation has now raised more than $2 billion from more than 200,000 donors, including many of the world’s richest and most powerful people and corporations. Foreign governments have also given money; the governments of Australia, Norway and Saudi Arabia have all given between $10 million and $25 million.

In 2005, the Clinton Foundation launched the Clinton Global Initiative, which is the best known and most public arm of the organization. CGI holds a glitzy annual meeting in New York that brings together leaders of private companies, nonprofit groups and governments to talk about how to solve world problems.

The event was designed to be a new model in global philanthropy, a global schmoozefest convened by Bill Clinton to bring people together to talk about how to solve world problems. At CGI, individuals and companies make public pledges to embark on their own charitable efforts, with CGI monitoring their progress. The conference is also a fundraiser for the foundation, because it is sponsored by private companies and all of those who attend, except nonprofit groups, pay membership fees to take part.

Unlike the Clinton Family Foundation, the Clinton Foundation does much of its charitable work itself, rather than making grants to other groups. It funds initiatives to combat disease and poverty, improve education, fight climate change, and promote women and children around the world.

In 2013, after Hillary Clinton stepped down as secretary of state, the William J. Clinton Foundation formally changed its name to the Bill, Hillary and Chelsea Clinton Foundation. The foundation has indicated that if Hillary Clinton is elected president, her and Chelsea’s names will be dropped and it will become, formally, the Clinton Foundation. It has also said it will cease accepting foreign and corporate donations. Regardless of the election results, the foundation has said next month’s Clinton Global Initiative will be its last.

6. When people give to the Clinton Foundation, what do they get in return?

The Clinton Foundation is a globally recognized philanthropy, known for helping to lower the cost of AIDS treatment and other drugs in the developing world. Its donors have traditionally included a bipartisan array of corporate leaders and ordinary people. If asked, many would say they gave simply to support the charitable aims of the organization.

As is not uncommon in the world of charity, donors also received prestige from being associated with the well-known organization, a reputational benefit boosted by the group’s association with Bill Clinton, a globally popular figure.

Critics charge that donors also gave to curry favor with the Clintons, particularly Hillary Clinton, who has held public office and presidential ambitions for most of the foundation’s existence.

Trump and other Republicans have alleged that Clinton Foundation donors were given favors by Hillary Clinton’s State Department. Emails have emerged showing how some foundation donors were able to gain access — particularly in making requests for meetings — to Clinton’s closest aides and sometimes to Clinton herself. But the emails show that the donors did not always get what they wanted, particularly when they sought anything more than a meeting. And there is no evidence that foundation donors received special treatment in direct exchange for their contributions.

7. When people give to the Donald J. Trump Foundation, what do they get in return?

That’s a lot harder to say.

The Trump Foundation’s biggest donors have been unwilling to talk about it.

Since 2007 — when Trump stopped being the Trump Foundation’s major donor — the biggest gifts came from Vince and Linda McMahon, the WWE wrestling moguls. They gave $5 million.

They declined to comment on why they gave.

The second-biggest donor in that period was a New York man named Richard Ebers. He gave about $1.8 million.

He declined to comment on why he gave.

The third-biggest donor was NBC, which broadcast “The Apprentice.” It gave $500,000 in 2012, the same year that Trump suddenly began promising more “personal” gifts to celebrity contestants’ charities (and paying with the Trump Foundation’s money).

NBC, also, declined to comment.

Among the other, smaller donors, a few would talk about their motivations. One won an online auction, where the prize was a lifetime membership at Trump’s golf clubs. Another was a friend of Trump’s, who said he didn’t know what else to give him.

And there was one who seemed surprised to hear that her company had been listed as a Trump Foundation donor at all.

“That’s incorrect,” she said, when informed that Trump’s foundation had listed her firm as giving $100,000. “I’m not answering any questions.”

Then she hung up.