A legally enforceable agreement between an employer and an employee. It can impose duties on both the employer and the employee. They are normally, but not always, written down, and normally you are given your contract before or when you start work. But the courts will rule that a contract exists between you and your employer if you have agreed to perform a task in return for payment.
Some terms of a contract of employment may not be written down, but are implied by law or by custom and practice in your workplace. For example, the employer's duty to provide a safe, secure and health environment is implied by law into all contracts of employment.