What is the main difference between an employee and a contractor?

An employee works under an employment contract, receives a regular salary, and is entitled to statutory benefits — the employer withholds taxes and contributes to statutory funds like CPF (Singapore) or Social Security (US). A contractor is self-employed, invoices for work completed, manages their own taxes, and is generally not entitled to employee benefits. The key distinction is control and integration: employees work under the direction of the employer; contractors control how and when they deliver their work.