Unit vectors and quaternions This might be a dumb question but recently I came to know about the quaternion number system.
I can't stop wondering, "Are they related to unit vectors in any way? They have similar notations and both seem to be related to Spatial dimensions."

As Don Thousand explains, you do need a bit of Linear Algebra/Abstract Algebra to fully appreciate the relationships. I would also add some elementary Complex Analysis (just the operations and basics) to also appreciate/understand. But for an application of quaternions and their vector connections, with a bit of the Math thrown in, I really do not think you can do better (at an elementary level) than the videos by 3Brown1Blue:
Visualizing quaternions (4d numbers) with stereographic projection
Quaternions and 3d rotation, explained interactively
