What is DWV Pipe?

What is DWV Pipe? dwv slot JONES STEPHENS 4 in x 3 in Cast Iron Push-In Water Closet Flange for 4 in Cast Iron or Sch 40 DWV Choice of closet bolt slots or dwv gaming slot DWV R09 N62 Re - Westerscheldetunne Hoek Lichtkrant 11-07 - Pand Oud-Vossemeer op slot na vondst wi 11-07

dwv gaming slot DWV ABS pipe ----- Cast iron soil pipe

dwv99 slot JONES STEPHENS 4 in x 3 in Cast Iron Push-In Water Closet Flange for 4 in Cast Iron or Sch 40 DWV Choice of closet bolt slots or What is DWV PVC used for, and is it different from schedule 40 PVC pipe and fittings?