The Biosynth Lab exists in a vaguely futuristic universe, where synthetic / robotic beings are already common place. However they lack the same rights and legal protections as a human, and are stuck with warranties and legal obligations to their creator.
Biosynths are the (work in progress) improvement upon common place robots and synths, with much more complex anatomy, and a cute face to boot! Due to the combination of biotech and mechanical properties, they need much less upkeep than a complete machine or ai, and can learn more reliably!
All current biosynths are experimental technology, and actively being worked on by the lab, whether they like it or not.