Thirty years ago, if you liked a movie, TV show, or a book you had to hope that your friends and family also partook in it so that you could discuss it with them. Nowadays you can simply search it up and scroll through what potentially thousands of people have to say about it in their fandoms.
Fandom: though the word hasn't existed long, what it describes has. One could argue that fandoms have existed since early civilizations, but this article focuses on fandoms in the modern era. For those of you who aren't internet slang savvy, fandom refers to any group of people who like and talk about virtually anything, although most fandoms center on pieces of media (TV shows, movies, books, etc.). The term can, in theory, be applied to anything so long as people like and discuss the thing, they are ,in general, ambiguous things, but for the sake of this article we shall focus on media based fandoms. You'll find hundreds of blogs dedicated to pictures of a certain celebrity, styles of architecture, and other specific things that you've never thought about how much you like. One doesn't even have to like the piece of media in question, or consume said media to be a part of the fandom. The only thing that qualifies one to be in a fandom is to know about the piece of media and peruse fan made content of it. For example, the popular first person shooter game, Overwatch, has a very large fandom but not everyone in it plays the game itself. They may have seen fan art or a game clip, and decided to look up more.
Fan content is what drives the economy of a fandom. Fanart and fanfiction (fan made fiction of the piece) are the proverbial king and queen of fandoms, but there are many different ways fans show their love or interest. There are long discussions of a character, a specific scene, and sometimes even one line a character says that merits a debate on the internet. There are headcanons: stuff fans think about certain characters. They can range from a character being LGBT, being autistic, certain behavioral quirks they may have, to little things a character might do, like a hobby. Anything that isn't explicitly said or denied in the piece of media itself is up for fans to decide.
Photo edits, screenshots of cool or important parts, quotes, and memes based on certain parts also shape a fandoms economy, but perhaps the most important aspect of most fandoms is shipping. Shipping refers to a person wanting two or more characters to be in a relationship, or shipping them. Most ships are of a romantic nature but occasionally there are ships founded on wanting characters to simply be friends. From ships come fan art (from not-safe-for-work to soft fluffy pieces), fanfics, and headcanons about what they might do as a couple. Indeed, one can argue that fandoms largely revolve around their ships.
Ships certainly cause the most conflict within a fandom, otherwise known as “discourse.” Often times you'll find people arguing over which ships are original, unoriginal, don't make sense, and if they have any problematic aspects. These are dramatically named “shipping wars.” While most of the time it mostly involves honest discussions, shipping wars can take a dark turn with personal insults and death threats, and with the anonymity the internet provides, the opportunity for malicious behavior is abundant.
This sets a negative image of the fandom, and sometimes the piece of media itself.
This is simultaneously the best and worst thing about being in fandoms. The only thing you have in common with these people is the fact that you know and talk about this thing; besides that, nothing is guaranteed. It allows you to hear the thoughts of people very different from you on the same thing you enjoy. Someone whose race, ethnicity, sexuality, religious beliefs, physical and mental conditions, are different than yours commenting on the same thing you enjoy can broaden your view on the work, and hopefully your worldview on a whole.
Of course, one has to take into account that racists, homophobes, xenophobes, transphobes, and other various bigots also exist in these fandoms and bring with them negative fan content in this space. And unless you have the means to take away their ability to post said content in your fandom space, there's nothing you can do besides block them, and try to avoid their content.
I posit however, that the goodness that fandoms can garner far outweighs any negativity they may foster. They allow people to discuss, share, and discover new ideas about their favorite characters. They serve as a space for people to show their love of something in creative and passionate ways. And perhaps most importantly, they let people know that they aren't alone in their love of said thing or a character.
Anything that does all that, can't be all that bad.