Subscribe to channels that you like in order to see more content from those channels. You can find a Subscribe button under any YouTube video or on a channel's page. Once you subscribe to a channel, any new videos that it publishes will be displayed in your Subscriptions feed. You may also start receiving notifications when a channel that you subscribe to publishes new content. By default, we'll only send you the highlights from the channel. Learn how to manage your notifications.

Learn more: https://support.google.com/youtube/answer/4489286