YouTube banners are used on channel pages to add branding. They are limited to specific sizes so that is works exactly perfect. The banners below are all being used by YouTubers to give proper branding to their creations.
It is also possible to make avatars that use elements of the banner branding to re-enforce the branding when the YouTuber comments it adds authority to their words and builds the brand.
These logos are of course also used by some of the YouTubers in the video as intro image, end image or buffers between items.
