This document defines key terms related to sanitary pipe work systems. It explains that sanitary pipe work allows for the transfer of wastewater and sewage from buildings to foul drains and provides ventilation to prevent odors or gas buildup. It then defines terms like soil waste, soil pipe, branch soil waste pipe, waste water, waste pipe, branch waste pipe, discharge stack, ventilating stack, branch ventilating pipe, building drain, and building sewer that are all components of efficient sanitary pipe work systems. Diagrams are provided to illustrate a typical plumbing system.