She is one of the world's richest and most influential people — but chances are you've never even heard of her.
Laurene Powell Jobs is far from a household name.
And the widow of Apple co-founder Steve Jobs prefers it that way, deliberately keeping a low profile and choosing to stay relatively anonymous despite her immense $29.3 billion fortune.
But behind the scenes, the mother-of-three is quietly but determinedly changing the world, thanks to her ambitious philanthropy project, Emerson Collective.
Ms Powell Jobs launched the collective back in 2004, and it has since become what the Washington Post recently described as "perhaps the most influential product of Silicon Valley that you've never heard of".
When her husband died of pancreatic cancer in 2011 at the age of 56, she inherited everything, instantly catapulting her to the sixth-richest woman on earth and allowing her to pour her considerable resources into the collective and causes close to her heart.
A decade after starting Emerson Collective, it still had just 10 employees, and even today, after the team has expanded to 130, most people are unaware the non-profit organisation even exists, let alone what it actually does.
Part of the reason is because Emerson Collective is complicated, unique and almost impossible to define.
But in a nutshell, it's an organisation dedicated to wide-ranging social change, by tackling issues including gun control, education reform and clean energy through media campaigns (it is the majority owner of news magazine The Atlantic), activism and social programs.
Ms Powell Jobs, 54, has assembled an all-star cast to the ranks to fight for causes she holds dear, including former Obama education secretary Arne Duncan who is fighting gun violence in Chicago, fellow Obama administration alumni Russlynn Ali, who co-founded Emerson's education reform initiative the XQ Institute, and renewable energy expert Andy Karsner, who runs various environmental programs.
Today, the collective invests in a number of private companies, allowing it to support advocacy groups, launch new campaigns and contribute to political organisations.
After a slow start, Emerson Collective stepped up its growth and activism through various high-profile campaigns last year, airing an hour of live TV featuring celebrities discussing the need to rethink the US high school system.
It also worked with artist JR to create "guerrilla art" on both sides of the US and Mexican border to protest against President Donald Trump's wall, and Ms Powell Jobs also owns a 20 per cent share of a company which owns a number of big-name sports teams.
In the Washington Post piece, Emerson Collective was described as "equal parts think tank, foundation, venture capital fund, media baron, arts patron and activist hive" — an organisation that defies definition and breaks the mould.
"I'd like us to be a place where great leaders want to come and try to do difficult things," Ms Powell Jobs told reporter David Montgomery.
"I think we bring a lot more to the table than money. … If you want to just be a check writer, you'd run out of money and not solve anything."
Despite her vast wealth, Ms Powell Jobs, who met her husband in 1989 when they sat next to each other at a Stanford Graduate School of Business lecture by chance, came from humble beginnings — her father, a Marine Corps pilot, died when she was three, and her mother struggled as a single mother of four.
The children realised at an early age that education was the key to getting ahead in life, sparking a lifelong passion for access to education which Ms Powell Jobs channels into Emerson Collective projects.
As the Washington Post describes, for Ms Powell Jobs, "It all has to do with democratising access and opportunity for voices she thinks have been shut out".
But perhaps the best summary of Ms Powell Jobs' personality and motivation comes from Billy Moore, a case manager with Chicago's Inner-City Muslim Action Network, which has worked alongside Emerson's anti-violence program Chicago CRED.
"She blends in with the crowd, yet she's probably the most powerful woman in the world," he told the Washington Post.
"She has power. You can see her true character is being a humble woman. She don't use her power to steal attention from what's going on."