Subscription

A subscription is a feature whereby one receives the latest additions to a YouTube user's videos, a YouTube tag, a YouTube search term or a YouTube playlist. There are two types of subscribing to videos:


 * clicking the yellow "subscribe" button at either the top right or top left of the page
 * going to "my subscriptions" and entering a tag or two to the search box that says "Subscribe to Tags", and hitting subscribe.

A user cannot subscribe to another user's subscriptions, as those are kept private.

RSS
The above is separate from subscribing to an RSS feed which syndicates YouTube videos to applications and websites outside the site. One can syndicate user playlist subscriptions as an RSS feed, however.

Channels by Subscription
The following is a chart featuring a list of the 30 most subscribed YouTube channels, including VEVO channels (as of June 29, 2013)