Getty Images Google celebrates its 21st birthday this month

Google turns 21 on Friday 27 September. The popular search engine is used by people right across the world and it's become a really important part of the internet for many.

To mark the special day we've got 21 facts about the tech giant that you might not know, unless you've already googled them yourself, of course!

1. Perhaps unsurprisingly, Google is the world's most visited website. It's even one of the most-searched terms on Bing.

2. Google was started by two college students called Larry Page and Sergey Brin. They wanted to create a website which would rank pages based on how many other pages linked back to them - a bit like a web.

3. The word Google comes from the term 'googol', which is the number one followed by a hundred zeroes. The creators chose it to reflect the huge amount of data they were searching through.

4. The first ever 'google doodle' (when Google's homepage changes to mark an important event) was created in celebration of the 1998 Burning Man Festival. The founders wanted people to know why they were out of the office.

5. Some of Google's most memorable doodles have celebrated the discovery of water on the Moon, and John Lennon's 70th birthday which was the first ever video doodle.

6. The first Google server was stored in a custom case made of Lego.

To enjoy the CBBC Newsround website at its best you will need to have JavaScript turned on. Google: What do you search for?

7. Google's headquarters is known as the Googleplex and is based in California's Silicon Valley.

8. At the Googleplex, there is a giant statue of a T-Rex dinosaur, which is often covered in flamingos. Rumour has it that this is a reminder to Google employees not to allow the company to go extinct.

9. Its headquarters are huge and there's lots of greenery. However, instead of lawnmowers, Google hires goats to keep the grass trimmed.

10. Google was the first big tech company to offer free meals to people who work there, and it allows employees to bring their dogs to work too.

Reuters Jennifer Lopez recently wore the same Versace dress during fashion week in Milan

11. Google Image Search launched in July 2001 and was inspired by the green Versace dress which Jennifer Lopez wore to the 2000 Grammy Awards. The dress became the most popular search query on Google - but there was no way to actually see it!

12. Google first announced its e-mail service, known as G-mail, on April Fool's Day in 2004. As a result, many people thought it was a joke!

13. The verb 'google' was added to the Merriam-Webster dictionary in 2006, which defines it as "to use the Google search engine to obtain information on the World Wide Web".

Getty Images The video-sharing platform has been part of the Google family for more than 10 years

14. YouTube became part of the Google family in 2006, after it was bought for more than $1.5 billion. At present, YouTube has nearly 2 billion monthly users, with more than 400 hours of video uploaded every minute.

15. The internet was 'broken' by a programmer at Google in 2009, after they accidentally added '/' to Google's blocked website registry. There is a '/' in nearly every website created, so nothing online could be accessed.

16. 15% of the searches made every day on Google have never been searched before.

17. In April 2018, Google became the first company to achieve 100% renewable energy. This means that it is able to purchase a kilowatt of renewable energy for every kilowatt it uses.

18. Google actually has at least six birthdays, but it chooses to celebrate it on the 27th of September.

19. Google has a lot of little tricks. For example, if you search 'askew', all of the results turn crooked.

20. Just one Google search uses around the same amount of computing power it took to send the Apollo 11 astronauts to the Moon.

21. Nowadays, Google is far more than just a search engine. Future developments are set to include artificial intelligence, a new streaming-based gaming platform, and even driverless cars.