Liège to Genk train with Regional

Intercity is a broad classification for express train services that connect cities over longer distances than commuter or regional trains, often with limited stops and comfortable carriages for long-distance travel. The term "InterCity" originated with British Rail in 1966 for its electrified West Coast Main Line services.Today, "Intercity" or "IC" is a brand name used by various railway operators across Europe and other parts of the world, including PKP Intercity in Poland, Trenitalia in Italy, and services in countries like Sweden and Ukraine. These trains typically offer both Standard and First Class seating, with amenities such as power sockets and luggage space. While some Intercity services are modern and high-speed, others may use older rolling stock, with speeds generally up to 160 km/h (100 mph).

The term "Regional" can refer to different train companies and services depending on the country. In Germany, "Regionalbahn" (RB) is a type of local passenger train that typically stops at all stations on a given line, connecting cities to their surrounding areas. Many RB trains are operated by DB Regio, a division of Deutsche Bahn, but other companies also run these services.