'Session' is Latin for 'a sitting' — from 'sedere' (to sit). A bounded period of gathered activity.
A period devoted to a particular activity; a meeting of a deliberative or legislative body; a period during which a court of law, parliament, or other body conducts its business.
From Old French 'session' (a sitting, a seat), from Latin 'sessiōnem' (accusative of 'sessiō,' a sitting, the act of sitting down), from 'sessus,' past participle of 'sedēre' (to sit), from PIE *sed- (to sit). A 'session' is literally 'a sitting' — the period during which a body sits together to conduct business. The PIE root *sed- is extraordinarily productive: it gave Latin 'sedēre' (to sit), 'sēdēs' (seat), 'sella' (chair, from *sed-lā), 'solium' (throne), and 'subsidium' (reserve troops sitting behind the front line, hence 'subsidy'); Greek 'hédra' (seat, base, hence 'cathedral,' 'polyhedron'); Old
A 'session musician' — a hired instrumentalist who records with various artists — takes the name from 'recording session,' itself from the parliamentary sense of a scheduled sitting. The word has traveled from a Latin law court (a sitting of judges) through Parliament (a sitting of legislators) through the music industry (a sitting for recording) to computing (a user session, a login session). Each domain borrowed the