In this chapter, the following terms have the meanings indicated. Terms Defined. “Applicant” means an individual who submits a request to be considered for employment by the Service after the Service announces that it is seeking applicants. “Board” means the Board of Directors of the Service. “Classification” means the descriptive title assigned to a single position or group of positions that are similar in duties, responsibilities, and minimum qualifications, and have the same pay grade. “Demotion” means a change from one position to another position which has a lower maximum pay grade or reduced duties and responsibilities. “Director” means the Executive Director of the Maryland Environmental Service. Employee. “Employee” means an individual who is hired or who transfers to a position under the regulations, policies, and procedures of the Service's human resources system. “Employee” includes a contractual employee, a senior management employee, and a temporary employee. “Employee” does not include an inmate or patient in a State institution who is employed by the Service. “Human resources system” means the Service's personnel system established by this chapter. “Leave” means official absence from Service duties and responsibilities. “Overtime” means work in excess of 40 hours per week. “Performance appraisal” means an evaluation of an employee's work performance based on predefined duties and responsibilities as described in job descriptions and performance planning documents. “Physical and mental qualification standards” means job-related physical and mental criteria necessary to perform the essential functions of a specific position. “Position” means a set of duties and responsibilities which are or could be performed by a single individual. A position may be either filled or vacant, full-time or part-time. “Probation” means a trial work period. “Promotion” means a change from one position to another position which has a higher maximum pay grade and increased duties and responsibilities. “Service” means the Maryland Environmental Service. “Supervisor” means an employee who is authorized to direct or manage another employee's duties, responsibilities, and access to benefits. Temporary Employee. “Temporary employee” means an individual hired by the Service for a period not to exceed 6 months. “Temporary employee” includes a student employee.