S / Slip / Socket – Glue connection that will accept pipe

Sp / Spig / Spigot – Glue connection into another fitting

T / Th / Threaded – Threaded connection

TOE – Threaded on end, usually on nipples

TBE – Threaded both ends,  usually on nipples

FPT / FIPT – Female pipe threaded

MPT / MIPT – Male pipe threaded

INSERT – Male hose barbed to insert and grab hose