eBike technology explained

Hey everyone!

I'm looking to dive a bit deeper into the tech side of eBikes, especially since I'm thinking about upgrading my commuter e-bike soon. For those of us looking at new bikes, what are the absolute must-know technological aspects that really make a difference in the ride experience, especially for mixed terrain commuting (think hills and flats)? I'm particularly curious about how different motor types (hub vs. mid-drive) and battery chemistries translate into real-world performance and longevity. What tech features should a new buyer prioritize understanding beyond just the basics?