Home timeline
The home timeline is what you see when you log in to your Mastodon server. Here is a screenshot of my home timeline:
Unlike on Twitter, there is no algorithm that curates the home timeline for you. Your Mastodon server lists all posts it is aware of in reverse chronological order, i.e., newest first. But which posts exactly show up in your home timeline?
Post types
The first type is from users you follow. E.g., I follow Privacy Badger and therefore my Mastodon server downloads the following post and user info and displays it in my home timeline:
The second type contains a followed hashtag. In this example, I do not follow the user who posted, yet the post shows up in my timeline because I follow hashtag #svelte:
The third type is boosts, which correspond to retweets. Since Mastodon does not use an algorithm to decide which boosts it displays, it displays all boosts. Here is an example:
Mastodon makes it visual who is the original poster and who boosted the post.
Other users' boosts and posts with hashtags in your home timeline are the main way to discover new users and content. But the home timeline is not the only timeline where you can discover new stuff.
Local timeline
A big difference between Mastodon and Twitter is that there is only one Twitter, but there are many Mastodons. Or rather, many Mastodon servers. This matters most at the beginning of your Mastodon journey, when you have to choose one of the many Mastodon servers as your home base.
Many servers make all public posts of users who have their home base on that server available in a special timeline, the local timeline. Some servers make the local timeline publicly available and discoverable.
For instance, if you are into front-end web development, you can explore the local timeline of front-end.social, a Mastodon server for the front-end development community:
If you did not already know CSS wizard Stephanie Eckles, you could have discovered her Mastodon profile via front-end.social's public local timeline.
Especially at the beginning of your Mastodon journey, when you are still seeking people to follow in your home timeline, public local timelines on specialized servers are great for discovering people.
Remote timeline
The third timeline, the remote timeline, shows the most recent public posts from users followed by users on this server. In other words, the remote timeline gives you a glimpse of whom other Mastodon users follow.
Here is the screenshot of the public remote timeline on front-end.social:
On servers with many users, the remote timeline can be an un-curated fire hose of posts. Therefore, the remote timeline is less useful for discovering new users than the local timeline. But you should know it exists.