Originally Posted by
tom tulpe
EC = international train (EC = "
EuroCity"), usually hauled by a locomotive and consisting of first and second class cars with a restaurant or bistro car. These cars may be provided by any of the countries the train passes through (e.g. a Budapest - Vienna EC train can be Austrian or Hungarian rolling stock).
The description is accurate but the example is outdated: apart from night trains, all Budapest - Vienna trains are now Austrian Railjets.
In general the EC "brand" is diminishing year-by-year as more services are operated by newer rolling stock such as ICEs and Railjets.