Video ads can run on:
- YouTube only
- YouTube and the Display Network
- The Display Network and video partner sites and apps
- YouTube and video partner sites and apps
Explanation:
While video ad content must be hosted on YouTube, video ads can appear on YouTube and on video partner sites and apps across the Display Network, including on tablets and mobile devices (depending on your format and settings).
Video ads can appear on YouTube and on video partner sites and apps across the Display Network.
Read more here: https://support.google.com/partners/answer/2375464