What Is Mastodon & Why Is Everyone Talking About It?

Prepare to start hearing a lot about instances, toots, and boosts. These are the trademarks of Mastodon, a social network that appears to have come out of nowhere, yet is so popular, you can’t even register for an account on the site's main social platform right now.
What exactly is the mysterious Mastodon? The free social network describes itself as a “a decentralized alternative to commercial platforms” that “avoids the risks of a single company monopolizing your communication.” That statement sure seems to be directed somewhere specific...
According to The Verge, Mastodon's founder, Eugen Rochko, created the social network out of his frustration with the changes being made on Twitter. After Twitter updated its conversation format last week, annoyed users took to Mastodon. The social network now has 41,702 users on its flagship social "instance," which would, presumably, have more if its server could handle the current influx of registration requests.
Instead of one single site, Mastodon has what's known as "instances." Each "instance" is a different server that you can sign up for, on which to interact with other users. You can also create your own. There's currently one for memes, another for animal rights, and there's the flagship channel, Mastodon Social, which is the most popular and is not currently accepting new users.
The posting process and feed and are similar in appearance to Twitter, except that retweets are now boosts and tweets are now toots. However, according to Mastodon, there are a few things that set it apart. Instead of Twitter's 140 characters per post, you get 500. Your timeline is entirely chronological, there are no ads, and each post has its own privacy settings.
Will Mastodon fizzle after a few weeks or take off and become the next Facebook, Instagram, or, well, Twitter? It's anybody's guess. But if anything, users are intrigued.