Women have always appeared in the Fortune 500 rich list here and there, but it’s only recently that their roles have become newsworthy – mainly thanks to two powerful women taking top jobs at the world’s biggest tech brands. As these companies become more powerful on a global scale, the actions of their CEOs come under scrutiny on a daily basis; if the CEO happens to be female, you can practically guarantee a news story will follow.

In this article, we’ll look at four female entrepreneurs that have climbed the ranks to positions of power.

First, there’s Sheryl Sandberg, the woman who assists CEO Mark Zuckerberg at Facebook. Sandberg is an ex-US government employee and was previously a high flyer at Google before becoming the first woman on Facebook’s board. Her official title is chief operating officer, and she appears regularly in the press.

Sandberg is a vocal believer in women’s ability to graduate towards senior roles in business, and her book Lean In is dedicated to discussing the topic. She extensively analyses the possible reasons for women holding back in the workplace. She also believes women should be comfortable in their own skin, particularly in a corporate environment, and is keen to promote equality at work and in the home.

Ursula Burns has served exactly three years as CEO of Xerox and has been tasked with the modernisation of the brand – no mean feat for a company that was founded more than a century ago. Her appointment is notable in the US: she was the first ever woman of colour to be in charge of an enterprise as massive as Xerox, and she is in the top 20 most powerful women on the planet.

On the company’s homepage, Burns says she values “ethical business practices”, and openly criticises organisations she believes to be sexist or discriminatory. It is estimated that she earned a cool $9.9 million last year, and her 2011 salary was comparable.

Marissa Meyer is perhaps the best-known example of a female CEO hitting the headlines. Now in charge of Yahoo!, Meyer started her working life at Google when the company was just starting out. Her speciality was A.I., and she quickly rose through the ranks to become Vice President of Search Products and User Experience.

Since 2012, Meyer has lead Yahoo! through a turbulent transition period. Rejecting extensive maternity leave, Meyer has banned employees from home working, although she herself worked from home towards the end of her pregnancy and paid to have a nursery built next to her corporate office. Despite ruffling feathers, she is determined to forge ahead with major changes.

With a background working in top jobs for The Walt Disney Company and eBay, and holding qualifications from Princeton and Harvard, Meg Whitman was well-placed to become CEO of Hewlett-Packard. Overall, Whitman is thought to be worth $1.3 billion; she spent $144 million on her campaign to become Governor of California three years ago. She lost.

Whitman has worked with some of the biggest names in the US, counting Steve Ballmer and Mitt Romney among former colleagues. At eBay, she was criticised for purchasing Skype, but that didn’t prevent HP from poaching her in 2011. Whitman is perhaps the most established high-profile CEO in the Fortune 500 list.

Sam Wright is a freelance writer working with prweekjobs.co.uk.