Barcelona Sants to Donostia-San Sebastián train with Renfe ALVIA

Renfe Alvia are high-speed trains with top speeds of up to 250km/h operated by Renfe, Spain’s national railway company. Alvia trains cover most cities in Spain, including Madrid, Barcelona, Bilbao, Valencia, Alicante, Zaragoza and Cadiz. They are somewhat slower than Renfe AVE and AVLO (high-speed and low cost) but cover more destinations and are a comfortable and effective way of travelling around Spain. Onboard facilities include free WIFI, bike storage and luggage allowance. Alvia trains have two seat classes – Estándar and Confort. Top routes for Renfe Alvia include Barcelona to Pamplona, Madrid to Cádiz and Alicante to Gijón.

Renfe MD, or Media Distancia (Mid-distance), is a division of Spain's national railway company, Renfe, specializing in regional train services. These trains connect cities and towns within the same autonomous community or between contiguous communities, typically covering distances under 300 km. Renfe MD operates various train types, including modern regional services with amenities like power sockets and reading lights, and high-speed Avant trains that reach up to 250 km/h on shorter, high-speed routes. While not as fast as long-distance AVE trains, Renfe MD offers extensive coverage across Spain, providing essential regional connections.

Renfe Intercity is a high-speed train service operated by the Spanish national railway company, Renfe. It operates throughout Spain, connecting major cities and towns with frequent departures throughout the day. The Intercity service offers a variety of train types, including the Alvia and Talgo, all of which offer comfortable seating and modern amenities. Alvia and Talgo offer fast trains but not as fast the high-speed trains like AVE, offering more stops. Passengers can choose from a range of ticket types, including Economy, Business, and First Class. Onboard facilities include Wi-Fi, power outlets, and a selection of snacks and drinks. The most popular routes for Renfe Intercity include Madrid to Barcelona, Madrid to Seville, and Barcelona to Valencia.

SNCF Intercités is the brand used by France's national railway company, SNCF, for its non-high-speed, long and medium-distance services on the classic rail network. Established in 2006, it encompasses routes not served by the TGV network, including both day and overnight trains. Intercités connects major regional cities and offers an alternative for destinations not on the high-speed lines, such as Paris to Clermont-Ferrand, Bordeaux to Marseille, and Nantes to Lyon. These trains are known for being comfortable and air-conditioned, with services like luggage space and, on some lines, Wi-Fi.

SNCF OUIGO is a low-cost train service launched in 2013 by SNCF, the French national railway company. It offers budget-friendly travel on both high-speed (Ouigo Grande Vitesse) and conventional (Ouigo Vitesse Classique) lines in France, and also to Belgium and Spain. OUIGO trains are characterized by a \no-frills\" approach, featuring a single class of seating and minimal onboard amenities to keep ticket prices low. While the high-speed services utilize specially reconfigured TGV trains, Ouigo Vitesse Classique uses older locomotive-hauled rolling stock for even cheaper fares on slower routes."