I use YouTube for everything. And while YouTube is in the top five websites in the world (No. 2 as of last year), I honestly think it is an underutilized resource. And while I, like everyone else, use YouTube as my source for cat videos, I've found so many other helpful videos as well.
1. Crash Course
Crash Course is a free online education resource that is slowly making its way into classrooms. Especially for people already fans of John and Hank Green's YouTube channel Vlogbrothers, this is a fun and entertaining way to study (in case the name is ringing a bell, John Green wrote "The Fault in Our Stars," "Paper Towns" and other best-selling young adult novels). Crash Course basically puts all the information you need out of your textbook into ten to fifteen minute videos that include key quotes, cartoon visualizations of the information, and a review of key themes at the end of the video. Because all the educators are also YouTube professionals, they speak quickly and in an engaging way (much more attention-catching then a professor speaking in monotone). 10/10 highly recommend. (Especially for AP tests and exam review.)
2. How To Adult
How To Adult is a YouTube channel in relation to Crash Course (as well as other associated educational resources), and while the title is pretty self explanatory, How To Adult videos range from how to write cover letter to how to remove stains and other how-to videos.
Most girls have searched makeup videos, but my favorite beauty YouTube channel is rclbeauty101. She not only does makeup tutorials, but also "real-life hacks:" how to get deodorant off clothes, how to get rid of bruises and acne, quick Halloween costumes and more. Her tips have saved me more times than I can count.
Then you get to the other spectrum. While I wouldn't consider myself some sort of fighting expert, I had to do a lot of fighting research for a story I was writing that included a lot of fight scenes. YouTube has tons of resources, though I did a lot of my research using FightSmartTrav, who goes over a lot of the basic punches, kicks, and moves that were relevant to my research (and probably to anyone who would like a self-defense class for free).
5. Interesting Information
Vsauce is another one of my favorite YouTube channels. Ever wonder why things are creepy and others cute? Why are bad words bad? Your answers await!
6. Health, cooking, and fitness
Gordon Ramsay has a channel that can teach you to cook like a pro, and lots of YouTubers have channels for yoga and workouts.
7. TED Talks
Also, TED Talks. There is literally a TED Talk for everything.
Anything you want to know, there are videos for it. If you want to learn a language, or any DIY project you can imagine, there is someone to explain it to you. And not only is it more fun, it's also a lot faster than trying to read through different web pages.
So continue to enjoy cat videos and videos of people falling, but also remember that YouTube also presents a wide range of free resources that are not only fun but also informative. Enjoy!