Frankfurt Airport long-distance station to Heidelberg Hbf train with Deutsche Bahn (ICE,RE,IC,EC)

Deutsche Bahn (DB) is Germany’s main train operator, running around 40,000 domestic and international services each day. Its fleet includes a variety of train types: high-speed ICE (Intercity Express) trains, reaching up to 300 km/h; IC (Intercity) and EC (EuroCity) trains for long-distance travel; and IRE (Interregio-Express), RE (Regional Express), and RB (Regionalbahn) services for regional and local connections. While bathrooms are standard on all trains, amenities such as onboard restaurants and free Wi-Fi are available only on certain train types and routes. DB offers a wide range of fares, including Super Saver, Saver, and Flexible tickets, along with discount cards like the BahnCard 25, 50, and 100. Additional options include single tickets, day tickets, and group tickets. Popular routes include Berlin–Munich, Hamburg–Frankfurt, Cologne–Stuttgart, Berlin–Dresden, and Hamburg–Cologne, as well as numerous regional services across Germany.

Intercity is a widely recognized brand for express train services that connect cities over longer distances, often with limited stops and comfortable carriages for long-distance travel. The term \Intercity\" originated in the United Kingdom in 1966 with British Rail's electrification of the West Coast Main Line, becoming a brand for their main-line passenger routes. Today, Intercity services vary across Europe, with some countries like Switzerland offering modern, high-standard trains, while in others, they may be older compared to newer high-speed options. Many European countries use \"InterCity\" as an official brand name for regular, long-distance train services meeting specific speed and comfort criteria. For example, PKP Intercity is a major Polish rail operator connecting cities and tourist resorts within Poland and across Europe. Trenitalia's Intercity trains in Italy offer an affordable and widespread means of rail transport, connecting various cities and towns. These trains typically offer Standard and First Class services, with amenities like power sockets and sometimes catering."

Rhein-Neckar-Verkehr GmbH (rnv) is a public transport company operating bus and tram services in the Rhine-Neckar region of Germany, including the major cities of Heidelberg, Mannheim, and Ludwigshafen am Rhein. It was established on October 1, 2004, as a joint subsidiary of five principal public transport operators that previously served the region, including the Oberrheinische Eisenbahn (OEG). The OEG, founded in 1911, originally operated narrow-gauge railway lines connecting Mannheim, Heidelberg, and Weinheim. Today, rnv operates over 80 lines, encompassing bus, tram, and narrow-gauge railway routes, and boasts the longest contiguous meter-gauge network in Germany. It serves approximately 500,000 passengers daily and plays a significant role in providing sustainable mobility in the Rhine-Neckar metropolitan region.