User ID must be enabled to recognize users across different devices.
To recognise users across different devices, what feature must be enabled?
- Attribution Models
- Google Ads Linking
- Audience Definitions
- User ID
The correct answer is: User ID
Explanation: User ID must be enabled to recognize users across different devices. When you implement User-ID, you can identify related actions and devices and connect these seemingly independent data points. That same search on a phone, purchase on a laptop, and re-engagement on a tablet that previously looked like three unrelated actions on unrelated devices can now be understood as one user’s interactions with your business.
User ID views include a set of Cross-Device reports, which aren’t available in other reporting views. The Cross-Device reports give you the tools you need to analyze how users engage with your content on different devices over the course of multiple sessions.
Read more here: https://support.google.com/analytics/answer/3123662