A Certificate of Service is a document which confirms that a person has completed a period of employment with a particular employer, or rendered a particular service. It is usually signed by the employer and serves as proof of the employee's work history. There are two main types of Certificate of Service: the Standard Certificate and the Enhanced Certificate. The Standard Certificate of Service is the most common, and includes basic information such as the employee's name, position, and period of service. The Enhanced Certificate of Service is more comprehensive, and includes additional information such as the duties performed, any awards or commendations, and the rate of pay.