DMF-Free Eco PU

What's the difference between OPC's synthetic PU leather and the traditional PU leather (wet and dry process)?
What is Water-Based PU (WBPU), what is PPU (Prepolymer PU), and what's the difference?
What is organic solvent? What is DMF?
What is DMFu (dimethyl fumarate)? How is it different from DMF?
What can OPC's eco-friendly PU leather be used on?
Isn’t Water-Based PU’s physical performance property weak?
What is "hydrolysis-resistance?" What is "non-yellowing?" What is "NOx-resistant?"
I have heard of Waterborne PU and Wet-Process PU. What are they? How are they different from Water-Based PU?
Is it true that water-based PU has a harder, more rigid texture that lacks the suppleness and softness of traditional solvent-based PU synthetic leather?