All employees have an employment contract with their employer. A contract is an agreement that sets out an employee’s:
employment conditions
rights
responsibilities
duties
These are called the terms of the contract.
Employees and employers must stick to a contract until it ends (for example by an employer or employee giving notice or an employee being dismissed) or until the terms are changed (usually by agreement between the employee and employer). If a person has an agreement to do some work for someone (like paint their house), this is not an employment contract but a contract to provide services.
Accepting a contract
As soon as someone accepts a job offer they have a contract with their employer. An employment contract does not have to be written down.