You may sometimes notice that YouTube features can look different across different accounts. This could be because you haven't updated to the latest version of the app, or because you're seeing an experimental feature or a feature that's rolling out.
What is an experiment?
An experiment is a test that we use to measure how YouTube users respond to new and improving product features, like search, sharing videos, and ads, among other things. We're always experimenting with ways to help people more easily find, watch, and share the videos that matter most to them. From time to time, you may notice some of these changes. We'll consider rolling out features more broadly based on your feedback from these experiments.
What is a rollout?
A rollout is a gradual launch of a new feature. Sometimes, to ensure a smooth launch, we don't show a new feature to every user at once. Instead, we start with a small percentage of users, and increase that percentage over time until 100% of users have the new feature.
If you'd like to share your thoughts on an experimental feature or a feature that's rolling out, please send feedback to let us know what you think.
* Nguồn: Youtube