A requirement may be an ethics and compliance safety that every business or job is mandating to know whether individuals that they are planning to hire fits the job that they need in the work.
"requirement" is nothing but the raw data gathered from the customer what he wants. "requirement specification" is a document which specify the requirements.
One requirement of obtaining a small business loan is that you have a prepared business plan. A plan entails detailed projections of earnings and expenses for the next five years.