铁路 (tiě lù) literally combines 铁 (tiě, 'iron') and 路 (lù, 'road' or 'path'), reflecting its historical origin as an 'iron road' — a track system built with iron or steel rails for trains. It refers specifically to the infrastructure of rail transport: the tracks, stations, signaling systems, and associated networks used by passenger and freight trains.

In modern usage, 铁路 commonly appears in formal, official, or technical contexts — such as railway bureaus (铁路局), high-speed railway (高速铁路), or railway tickets (火车票, though note that 火车票 literally means 'train ticket', not 'railway ticket'). It is distinct from more colloquial terms like 火车 (huǒchē, 'train') which refers to the vehicle itself. The word is neutral in register and widely understood across all Chinese-speaking regions.