This Ableton official tutorial covers the foundational mental model of how tracks work in Live, clarifying their dual role as clip containers and signal managers across both views of the DAW.
Session view lays tracks out as columns, while Arrangement view stacks them vertically with time running left to right. Despite the visual difference, both views share the exact same set of tracks, so the first track in Session is always the first track in Arrangement.
Each track has its own Detail view, where instruments, effects, and plugins are added and processed in a left-to-right signal chain. A track can only play one clip at a time, and it can pull from either Session or Arrangement view, but never both simultaneously.