The S8 is a regional railway line of the S-Bahn Zürich on the Zürcher Verkehrsverbund (ZVV), Zürich transportation network, and is one of the network's lines connecting the cantons of Thurgau, Zürich and Schwyz.
The line runs from Weinfelden and heads for the Zürcher Weinland, then it turns around at Zürich Hauptbahnhof and continues on the left shore of Lake Zurich to Pfäffikon (SZ).
The line's overnight service (SN8), operating on weekends after midnight, runs between Zürich HB and Lachen (SZ).
The ZVV (German abbreviation for Zürcher Verkehrsverbund, translated into English as Zürich Transport Network or Zürich Traffic Network) is a public transportation fare network system, combining virtually all kind of public transport means (rail, bus, tram, trolleybus, lake boat and cable car and the like) and services in the canton of Zürich (including Rapperswil-Jona and Pfäffikon SZ and some other spots), and integrating them into one single fare network and coordinated timetables. The fares are not based on particular lines and connections from A to B, but on the number of zones ones travels through for a specified period of time.
Established in May 1990, the ZVV was initially an elaborate web of railway lines. They were prefixed with the letter S (S-Bahn). S-Lines 1 through 43 (with some lines missing) now form part of the S-Bahn Network. A proof-of-payment fare system is in force on all S-Bahn trains; there are no fare gates, but those without a valid ticket face a minimum fine of CHF 100.