"Obligation" vs. "requirement": when words get demanding!

What is similar?

Both "obligation" and "requirement" refer to something that must be done. They both imply a necessity or duty that a person or entity is bound to fulfill.

What is different?

An "obligation" often has a moral, legal, or social aspect, implying a duty or responsibility that might not always be written or enforced by rules. A "requirement" is often seen as a condition that must be met, typically defined by rules, standards, or specific criteria.

Which one is more common?