By now, you're probably familiar with them. Chances are you've pulled up the Google search page, surprised and perhaps delighted to find the usual blue, red, yellow and green letters transformed to make the Google logo into a colorful cartoonish image to celebrate an important anniversary or holiday.

Google has been sharing its beloved Google doodles with millions of people around the world since 2000. The idea for doodles came in 1998 after Google founders Larry Page and Sergey Brin added a stick figure man to the search engine's logo. It was meant as a "comical message to Google users that the founders were 'out of office.' " And by out of office, they meant they were at the Burning Man festival.

Since then, Google has published thousands of doodles with help from the company's doodle team, which includes artists and engineers around the world, says Perla Campos, a Google doodle global marketing lead. Many doodles take more than a year of planning, with the team churning out about 400 a year.

Over the years, they've created doodles to celebrate a range of occasions — from children's first day of school to the 131st anniversary of the hole puncher. Some doodles are static; others are interactive or animated. As the Google logo alterations have evolved and grown more popular, the doodle team has recognized — and taken advantage of — the opportunity to use the illustrations to educate users.

Sometimes covering political or controversial topics, doodles can be "a catalyst for people to have critical conversations," Campos said.

A doodle earlier this year marked the 100th anniversary of the Silent Parade, during which almost 10,000 African-Americans marched in New York City to protest violence against African-Americans. After it appeared, a sixth-grade teacher contacted the tech giant to say thank you. The educator shared that the doodle created a space for conversation in the classroom around the sensitive topic, Campos said.

"It's a moment to teach you a lot about these people that history forgot, sometimes purposefully, because of the color of their skin," she said.

Doodles are also a way for the company to express some of its values, such as diversity and inclusion, she said. Campos, who is Mexican-American, remembers thinking at one point that she had never seen herself represented on the Google home page. That's when she pitched a doodle celebrating the late Selena, a Mexican-American artist whose music captivated an international, multicultural audience.

About two years later, the animated video doodle featuring Selena's hit song "Bidi Bidi Bom Bom" appeared. It was a significant moment not just for Campos, but for many Latinos.

"People from my community could see that and say, 'Google gets it,' " she said.

The messages Google was sharing with its doodles initially inspired future doodler Nate Swinehart to join the team.

Swinehart wanted to be part of the team after seeing the doodle honoring the opening of the 2014 Winter Olympics in Sochi, Russia. The doodle, which featured drawings of Winter Olympics athletes pictured on a rainbow background, made a statement, he said.

The rainbow colors, which symbolize gay pride, appeared above a quote from the Olympic Charter: "The practice of sport is a human right. Every individual must have the possibility of practicing sport, without discrimination of any kind and in the Olympic spirit, which requires mutual understanding with a spirit of friendship, solidarity and fair play."

At the time, multiple media outlets highlighted the doodle as a form of protest against Russia's anti-gay legislation and gay-rights crackdown.

"It was a total moment of empowering people," Swinehart said. "I was like, 'I want to be a part of that.' "

Swinehart later collaborated with a team of LGBTQ doodlers to come up with a concept for the stop-motion animation doodle celebrating Gilbert Baker's 66th birthday. Baker, a gay-rights activist in San Francisco, is known for creating the now iconic pride flag in 1978.

To honor Baker's creation, Swinehart filmed fabric pieces coming together to visualize the flag's creation. Looking back, he says working on the overall project was a very personal experience. He counts the doodle among his career highlights and as an important example of the powerful messages doodles can share.

"We're saying more with them," Swinehart said. "We're reinventing them technologically, but also topically."

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