The Dewey Decimal System is to a library what tags are to Tumblr: a means of organizing and searching through content that is often overlooked and misunderstood.

First to understand their importance, you must know what tags are.

In every Tumblr blog post you make—whether it be of a video or just plain text—users have the option of adding tags, or keywords, to identify the sort of content featured in the post. For example, if you posted a GIF animation of a fat cat jumping into a small box, some of the tags you may add would be “LOL,” “dog,” and “cute.”

The “LOL” tag, for example, is curated by an army of volunteer editors who, with the click of a button, can have a post appear on the tags front page. As a result, these posts typically collect hundreds of comments, likes, and reblogs—not to mention, a windfall of new followers for the person who originally posted the animation.

Aside from these curated tags, there is a whole world of community-generated (also know as “unmoderated”) tag pages that circulate around the site. Here’s a list of the top 10 user-generated tags for the last 30 days, courtesy of Tumblr Editor-in-Chief Chris Mohney.

1) One Direction
The British boy band has been dominating American airwaves since their performance on Saturday Night Live in April. This has been a similar story on Tumblr where the group is hands down the most popular user-generated tag, with people sharing photos, GIFs, and memorabilia from the group.

2) Exo
Not to be outdone by their British brethren, this Chinese-South Korean boy band is a Tumblr phenomenon.

3) Tom Hiddleston
If you were to judge actor Tom Hiddleston by the images on this Tumblr tag page, you would think the 31-year-old Brit only wore patent leather pants and looks of shock and awe. The actor from Thor and The Avengers is a Tumblr favorite.

4) Love
Everyone has a slightly different interpretation of the word "love." On Tumblr, the general consensus is that love can be used to describe a couple kissing, ice cream, and Bob Marley.

5) Harry Styles
The British teenager is one of the five members of One Direction who Tumblr swoons over.

6) Quotes
If you ever need an uplifting quote, or one to make you laugh uncontrollably, just check out this tag.

7) Larry Stylinson

An inside joke that stumped us here at the Daily Dot, Larry Stylinson is a mash-up of One Direction's Harry Styles and Louis Tomlinson, poking fun at the two's bromance. 

8) Legend of Korra
The Legend of Korra is a two-month-old animated TV series on Nickelodeon that has inspired hundreds of people on Tumblr to create their own fan art.

9) Loki
Loki may be the antagonist in The Avengers, but on Tumblr he’s the most beloved movie character around.

10) Funny
The tag “LOL” is the top one on the site, “funny” is also a great place to find content to put you in stitches.

Photo via Tumblr