Railway refers to a track or set of tracks made of steel rails along which passenger and freight trains run.
The term "railway" can also mean:
1. The entire system including tracks, stations, signals, etc.
2. A company that operates train services
3. In British English, it's commonly called "railway" while Americans prefer "railroad"
Fun fact: The world's first public railway was the Stockton and Darlington Railway in England, opened in 1825.