world · boundary

1. Origins, structure, and basic meaning

• Structure: 界 has 9 strokes and denotes a range, realm, or boundary separating areas.
• Basic usage: 視界 is read しかい, and 境界 is read きょうかい.

2. Common pitfalls and similar expressions

• Visibility and a dividing boundary
  • 視界が悪くなった means visibility worsened. 視界 concerns the area one can see or how clearly one can see it.
  • 二つの町の境界 is the boundary between two towns.
  • 仕事と休みの境界 is the distinction between work and rest. 境界 applies to physical places and abstract areas alike.