Jitesh Ubrani, an analyst at IDC, outlined the differences between Wear OS, formerly Android Wear, and Android. Simply put, the difference to developers is control. He said.
Brands who use Android in their wearables take the open sourced version and customize it to their liking and often include non Google services. Since the OS is open sourced, Google didn't have a say in how it's used or customized. WearOS on the other hand is Google's official OS built for smartwatches and thereby requires Google's "blessing."
The wearables and smartwatch makers using Android are typically in Asia. Devices using Android include vendors such as Mobvoi, Abardeen (V328, V118, V116), XTC (Z2 and Z3). Google lacks services in China.