違

Traditionally analyzed as a compound ideograph or phono-semantic compound:

辵 — semantic component meaning “to walk; movement”;

韋 — phonetic component indicating the sound (위 / wéi). The idea is of moving in a different direction, leading to meanings like deviation, opposition, or violation.
Semantic development: - to move in a different direction; - to deviate or differ; - to oppose or violate.

위반 (違反) — violation

위배 (違背) — contradiction; breach

위법 (違法) — illegal; unlawful

상위 (相違) — difference; discrepancy

違 is widely used in legal, logical, and everyday contexts to express violation or difference. The core idea is “going against the expected direction or norm.”
Related characters: 反 — to oppose

背 — to turn one's back; to betray

差 — difference