光

1. Origins, structure, and basic meaning

• Structure: 光 (ひかり) is a noun for light or a beam emitted by a source.
• Basic usage: It describes morning light entering a window or a lighthouse beam used as a guide.
  • 窓から朝の光が差し込んできました。 — Morning light entered through the window.
  • 遠くに見える灯台の光を目印にしました。 — We used the distant lighthouse beam as a guide.

2. Common pitfalls and similar expressions

• Light and its source
  • 光 is the light itself, while 灯台 is the lighthouse structure producing the guiding beam.