Views

Views are the amount of times a video has been watched by other users. They are essential to how YouTube works.

About
Views have been around since the beginning of YouTube. The more views a video has, the more money a YouTuber is likely to get, because advertisers pay to have their ads shown during videos of those with high view counts.

History
Originally, the term "viral" was used to define a video that had over 1 million views. Nowadays, the term is used more to identify videos with a view count of over 3 million rather than 1 million, because it is much more common for videos to get 1 million videos these days.

301 club
The term "301 club" was widely used in the 2011-2014 era of YouTube. It referred to a glitch in the way YouTube calculates views when a video is first posted. For a while the view count is stuck at the number 301, but eventually it is updated. YouTube stated they will eliminate this glitch in the near future.