The featured video has been replaced by a Channel trailer for non-subscribers. Think of it as a short video that welcomes people to your Channel and tells them what it is about and why they should subscribe.
You can create horizontal or vertical sections on your homepage based on popular uploads, recent uploads, all playlists, likes, recent posts, recent activities, a single playlist or a tag (i.e. all videos on your channel that have been tagged with the keyword submarines).
On the right side of the homepage is a section called Related Channels, which are selected by YouTube. You can hide this section by hovering over it and selecting disable. There is tradeoff. This will remove your Channel from showing as related on other Channels.
The section may be displayed as Popular, which means YouTube wasn’t able to determine which Channels are related to your Channel. In this case, YouTube will select Channels with the most views and subscribers.
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