MPV means multi-purpose vehicle. It's just a marketing term. In Europe, that is what they call their minivans. Hyundai calls their Matrix model an MPV. Yep, Mazda even named their van MPV. hehehehe.

Originally they were vans with flexible seating (turns into a bed, rotates, can be taken out, etc.). Pero ngayon halos lahat naman ng van flexible na ang seating system.