Differences Between Vinyl Flooring’s Foam Bottom and Dense Bottom

The vinyl flooring is made of PVC (polyvinyl chloride), which has five layers including UV coating, wear layer, printed layer, fiber glass, backing layer. The foam and dense bottom belong to the backing layer.
PVC flooring tile just has dense bottom. However, Vinyl Sheet has foam and dense bottom. Commonly, vinyl sheet flooring of less than 2mm are almost dense bottom. 2mm -4mm is foam bottom. Do you know the differences between foam bottom and dense bottom?
1.Price:
Dense bottom has high density, and that need a lot of raw materials. So it is expensive than foam bottom’s vinyl sheet.
2.Performance:
Compare with dense bottom, foam bottom has soft surface and excellent sound absorption and easy to install. However, dense bottom is more wear-resistance, stable and compressive, and that are more suitable for use in large commercial areas such as super market, hospital, hotel etc.