X (formerly Twitter) timelines are a list of tweets or messages displayed in the order they were sent, with the most recent at the top. Here’s what you need to know about them.

There are different types of X timelines. The Home timeline is what everyone sees by default. It’s a list or stream of tweets from everyone they follow, updated in real time.

There are also timelines generated by X-lists. These show posts from users included in a list you follow. These posts can come from lists of users created by you or lists created by others.

Search results also form X timelines. These timelines show posts that match your search query in a chronological list.