A few years ago, Bill Gates—who, with a personal worth of some $75 billion, remains the wealthiest man on the planet—said something interesting about money: He didn't need it anymore.

"Money has no utility to me beyond a certain point," the Microsoft founder said. "Its utility is entirely in building an organization and getting the resources out to the poorest in the world."

Gates was referring, of course, to the charity that bears his and his wife's name. The Bill & Melinda Gates Foundation is the largest private foundation in the world with the global reach to match.

The foundation has been Bill Gates' full-time job since he stepped down as Microsoft's chairman in 2014. Yet, while many people have heard of the organization, few can explain its work in detail—how it gives its money away and the effect all that money has had.

Part of the reason is the foundation's sheer complexity: It employs 1,300 people in eight offices around the world while funding 29 program areas via 1,400 grantees. Some of the opacity, no doubt, also has to do with the foundation's historically low-key approach to the media. But with some sifting through the foundation's public disclosures and help from the foundation itself, Adweek has broken it all down to the essentials.

How the foundation gives, and how it gets results

The Gates Foundation gives away somewhere between $3 billion and $5 billion annually. That seems like an awful lot of money, at least until Miguel Veiga-Pestana sets you straight on the matter.

"People talk about us being very large," says Veiga-Pestana, the foundation's chief communications officer, "but if you look at the pool of resources at scale, what we have to offer is relatively small." (Consider, for example, that the U.S. government plans to give $34 billion in foreign aid in 2017 alone, and you'll see his point.)

In fact, because its founder is so famous and its aims so ambitious—"to help all people lead healthy, productive lives"—it's easy to presume lots of things about the Gates Foundation, including that it's involved with lobbying efforts or political campaigns (it isn't) or that it makes grants to individuals doing good work (it won't).

Instead, the Gates Foundation works like a benefactor with many arms, and the majority of its money goes to a large number of entities (non-profits, for-profits, governments and so on) that administer the programs that align with the foundation's mission. And since the foundation concerns itself with so many causes—from AIDS to malaria, global poverty to disadvantaged high schools—it's really the only logical way.

Grants to Rotary International, for example, fund the service organization's global polio eradication efforts. In 2014, the Gates Foundation gave $24 million to Bloomberg Philanthropies (led by Wall Street titan and former New York City Mayor Michael Bloomberg) to assist with that group's efforts to end tobacco use. UNICEF and Johns Hopkins are Gates Foundation partners, and so are the World Bank and a number of for-profit companies.

This privately funded, management-based, data-driven approach to charity work—"philanthrocapitalism" is the term some use—is not without its critics. But the Gates Foundation's retort is that its method gets real, measurable results, which is all that counts. "We can't achieve anything of scale without a lot of partnerships," Veiga-Pestana explains. "We can't move the needle if we're not collaborating with governments and other organizations."

To the foundation's credit, it's also moving the needle on many causes other major charities pay little attention to. As CEO Susan Desmond-Hellmann recently put it, "We do things that others can't or won't."

Public computers for Latvia, high-tech seeds for India and bicycle commuting in Washington State—all are areas of interest to the Gates Foundation. Last year, it gave a $27 million grant to London's Natural History Museum as part of an initiative to address neglected tropical diseases. Gates money also funds something called the Reinvent the Toilet Challenge, which incentivizes inventors to create off-the-grid toilets for the 2.6 billion people who "don't have a safe and affordable way to poop."

Scanning the sheer number of funded causes on the its website, it's almost tempting to conclude that the foundation's goals might be too ambitious. But here again, Veiga-Pestana begs to differ. "Our vision should be bold," he says. "If you look at what we talk about, you might say, yes, that feels broad. But I'd argue it's quite specific. It focuses on improving health and empowering people to improve their lives."

It wasn't always this way. In the years he helmed his software empire, Bill Gates' charity work largely involved getting computers (equipped, incidentally, with Microsoft software) into libraries across the U.S. Only in 1994 did the tech titan seemingly become aware of the world outside of technology and the many problems that that world had. "I started to learn about poor countries and health," Gates recalled a few years ago during a speaking tour. "I saw the childhood death statistics, [and] I said, 'Boy, is this terrible!'"

In 1999, Gates combined three of his smaller charities to form the Bill and Melinda Gates Foundation, which has grown in both size and ambition ever since—in large part via the organizational and philosophical guidance of Melinda Gates, a fearlessly outspoken proponent of family planning and birth control, among other things.

In light of the size the foundation has grown to, Veiga-Pestana says it can be easy to forget that it's only 16 years old. "It started with four people above a pizza shop," he says. "We've grown immeasurably over that 16-year period." These days, the Foundation occupies a 12-acre, LEED-certified campus just down the street from Seattle's Space Needle—itself a metaphor for looking toward the future and thinking big.

One of the more interesting tasks the Gates Foundation plans to tackle in the future is the job of its own PR. Veiga-Pestana, who spent years in marketing for Unilever before taking on his current post, explains that while major brands enjoy a high level of public awareness but often lack trust, the Gates Foundation's position is the converse: "We have a high trust," he says, "but there's a lower degree of familiarity with the work we do."

Making a difference in the lives of the world's poor generates an enormous number of individual stories—ones the foundation plans to do a better job getting into the public eye in the years ahead. "We have the right issues to talk about and the science and data to validate what we're saying," Veiga-Pestana says. "What we could do more of is humanize—and tell stories that people can relate to."

Read more about how creativity and tech are fueling today's nonprofits in Adweek's Cause Marketing Report.