While the term "barcelona travel card" could be used to describe any ticket or pass for Barcelona's metro system, in the context of travel cards for tourists, it often refers to part of the offerings like the Hola Barcelona Travel Card, which includes unlimited access to the metro. The metro system in Barcelona is extensive, connecting major attractions and districts, making a metro card an essential tool for visitors. The metro card included within the Hola Barcelona Travel Card simplifies travel, allowing for easy hop-on, hop-off access to explore the city's sights.