What are male and female fittings?

What are male and female fittings are plumbing and piping terms describing type of threaded connection based on whether threads are on outside or inside, not related to gender but to mechanical design for joining pipes. Male fitting, also called MPT male pipe thread or MIP male iron pipe, has threads on outside of fitting, like bolt, designed to screw into female fitting. Male fittings include male adapter, male elbow, male coupling with external threads. Female fitting, also called FPT female pipe thread or FIP female iron pipe, has threads on inside of socket, like nut, designed to receive male fitting. Female fittings include female adapter, female elbow, female coupling with internal threads. To create watertight connection, you need one male and one female fitting of same size and thread type, often with Teflon tape or pipe dope to seal. In addition to threaded fittings, male and female can refer to slip fittings where male end inserts into female socket, like PVC where pipe inserts into female coupling. Understanding male versus female essential for buying correct parts and avoiding leaks, for example garden hose has male and female ends. So male and female fittings are complementary connectors that screw together to join pipes.