軸

1. Origins, structure, and basic meaning

• Structure: 軸 is read as じく and is a noun for a physical axle or for the central principle around which an activity or plan is organized.
• Basic usage: A mechanical part appears in 車輪の軸, while a planning focus appears in 交流を軸に.

2. Common pitfalls and similar expressions

• Physical and figurative senses
  • A wheel has a literal axle; a plan can have a figurative axis that organizes its elements.
• Difference from 中心
  • 中心 broadly means the center, while 軸 emphasizes a line or principle around which other elements turn or are structured.