YouTube officially reached preadolescence this year, with its 10th birthday. It remains the web’s most popular video website.

On YouTube, typically for free, you can watch homemade viral hits, comedy shorts, how-to tutorials, clips from TV shows and movies, and full-length original educational programs from such quality content creators as PBS, BBC, and TED. You can even listen to music.

You can consume YouTube content on devices ranging from PCs to smartphones and TVs to tablets. For quicker access, YouTube lets you subscribe to “channels,” which are the content provided by a specific YouTube account. YouTube also suggests videos it thinks you’ll like based on your previous viewing habits or their popularity.

YouTube was launched in 2005, and Google bought it a year later. Today YouTube is the third most popular site on the entire web, behind Google and Facebook, according to the Web analytics firm Alexa. Following YouTube in popularity are the Chinese search site Baidu, Yahoo, Wikipedia, Amazon, and Twitter.

The main competitors of YouTube are Netflix, which ranks 53rd in popularity, and Hulu, which ranks 297th.

YouTube also faces new competition from social media giants Facebook and Twitter, who have lately beefed up their efforts to incorporate video. Facebook is courting television networks, movie studios, and celebrities. Twitter recently rolled out the ability for users to share video clips up to 30 seconds long.

Upstart video services such as Vessel and Vimeo are also providing competition by trying to lure content creators away from YouTube with better offers.

YouTube isn’t standing still. To better compete with Netflix and Hulu, last year YouTube introduced a trial offering of 53 subscription channels with prices ranging from $0.99 to $6.99 a month. It’s also currently testing YouTube Music Key, which provides unlimited, ad-free access to music videos as well as 30 million songs for an introductory price of $7.99 per month.

But YouTube makes the lion’s share of its money through advertising, including banner ads, which are easy to ignore or click out of, and “pre-roll” ads, which aren’t so easy to ignore. The latter are much like TV commercials, and they precede the video clip. Some people mute the audio until the ad is over.

YouTube gives content creators the ability to share in the ad revenue generated from their videos. These can be large companies such as CBS, NBC, and Fox. But ordinary consumers can also become a YouTube “partner” by going to Account Settings, clicking on the Monetization tab, clicking on Enable My Account, and following the directions. With YouTube’s standard revenue-sharing agreement, content owners receive 55% of ad money.

Anyone can upload their own videos, so long as you register, which is free. Anyone can watch videos, even without registering, though registering gives you access to additional YouTube features, including rating specific videos and leaving comments about them, saving videos for later viewing, and creating a playlist of videos to watch.

Sharing a video on YouTube can be as easy as shooting the video with your smartphone and uploading it by clicking on the Upload link on YouTube’s main page. YouTube offers rudimentary video editing tools online and lets you provide a title and description. Promoting your video involves procedures from emailing out the URL link to embedding it in another webpage.

Like much about the Internet, YouTube represents a great democratization. Anybody can create as well as consume. But there are negatives to this as well, including excruciatingly boring video blogs in which amateur videographers believe millions of people want to see their largely vacant talking heads commenting about news events rather than seeing video of the events themselves. On the other hand, remarkably creative amateur videos are created as well.

In “prehistoric” Internet times, back in the early 1990s, government officials, telecommunications executives, and pundits were talking excitedly about the “information superhighway,” which was projected to encompass among other things “video on demand” and where personal computers and televisions were supposed to converge. We’ve now seen this happen with a number of different devices.

The surging popularity of Internet video is hurting the TV business. People in greater numbers, particularly young people, are “cutting the cord” with their cable, phone, or satellite company, obtaining video only through the Internet.