As the CEO of Apple, he's the first openly gay CEO in the Fortune 500.

And in 2018, Apple became the first U.S. company ever to be worth $1 trillion.

But compared to his counterparts in the tech world, his net worth is pretty modest.

Google founder and Alphabet CEO, Larry Page, is worth $53 billion.

Facebook CEO, Mark Zuckerberg, is worth just under $70 billion.

And Amazon CEO, Jeff Bezos is the first person in modern history to accumulate a fortune north of $100 billion.

Cook doesn't lead a lavish lifestyle, and has said, "I like to be reminded of where I came from, and putting myself in modest surroundings helps me do that."

The Alabama native had a humble start in life as the son of a shipyard worker and pharmacy employee.

When he was promoted as Apple's CEO in 2011, his base salary was $900,000, and has risen to $3 million in 2017.

He also receives a cash incentive based on the company's performance, which pushed his total pay for 2017 to over $12 million.

But his net worth consists mainly of $622 million worth of Apple's stock and options he has collected since becoming CEO.

And $3.4 million of Nike stock options he gets as a member of Nike's board of directors.

So, how does Apple's leader spend his fortune?

Quite differently than other CEOs of tech giants.

In 2012, he bought a 2,400 square foot home in Palo Alto, for $1.9 million.

The median cost of a home in Palo Alto in 2018 is $3.3 million.

And his frugality doesn't stop at the housing market.

He reportedly buys his underwear at Nordstrom's semi-annual sale.

But Cook does splurge when it comes to donating to good causes.

A philosophy that differs from that of his predecessor, who lacked a record of public giving.

He encourages his employees to give and has led Apple into many philanthropic endeavors.

In 2011, he instated a company-wide, nonprofit donation matching program.

Over the past 10 years, Apple has contributed $130 million to help RED fight AIDS.

$100 million to advance diversity in tech, through President Barack Obama's ConnectED initiative.

$50 million to hospitals and more.

Cook practices what he preaches, too.

He's donated to civil rights efforts.

And in 2018, he donated more than 23,000 shares of his Apple stock, valued at just under $5 million to an undisclosed charity.

He also regularly makes campaign donations.

He's hosted fundraisers for Barack Obama and Hillary Clinton.

And in 2016, he donated $236,000 to the Hillary Victory Fund.

Cook's altruism even applies to his future financial plans.

He intends to use his wealth to put his nephew through college.

And upon his death, he plans to give away all his money to good causes.

He told Fortune magazine, "You want to be the pebble in the pond that creates the ripple for change."

Windows 8 shipped about a year before Mavericks, and it's at 14%.