YouTube Premium (formerly known as YouTube Red) is a membership service made available by YouTube on the 28th of October, 2015. In May 16, 2018, YouTube announced that YouTube Red would become YouTube Premium, adding the recently announced YouTube Music, and changing the price to $11.99 per month (United States price).
The new YouTube Premium includes the following:
In addition to this, YouTube confirmed that this service will continue to expand and become available in new countries.
You can learn more about YouTube Premium here.