A diagram showing the different meanings of the word "platform" in the context of a railway station. The fictional station has 

1 island platform (green)
2 platform faces/platform tracks (blue)
3 independently signalable platforms (purple)
4 designated platforms (red)
(note that of the terms use only "island platform" is standard and unambiguous)
Own work, made using Inkscape 0.43
Chris McKenna (Thryduulf)