Section 51A. The following words as used in this and the following sections and in the classification and compensation plans shall have the following meanings:—

''Board'', the county personnel board;

''Class'' or ''title'', a group of positions forming part of the classified service established by sections forty-eight to fifty-five, inclusive, and sufficiently similar in respect to duties and responsibilities that the same descriptive title may be used to designate all positions allocated to the class, the same general entrance qualifications may be required of incumbents of positions in the class, the same general tests of fitness may be used to choose qualified employees and the same schedule of pay may be made to apply under the same or substantially the same employment conditions;

''Class allocation'', the official initial placing of a class in a job group in the salary schedule;

''Class reallocation'', the official subsequent placing of a class in a job group in the salary schedule;

''Employee'', employee or officer, unless the latter is otherwise specifically exempted;

''Increment'', the amount of dollars between any two consecutive steps-in-range in the same job group in the salary schedule;

''Job group'', a unit of the salary schedule which includes all classes in the position classification plan which are sufficiently comparable in value as regards duties and responsibilities, irrespective of the field of work of which they form a part, so that the same salary range may be made to apply to all classes in the same unit of the salary schedule;

''Position'', a job which may be held by an individual employee. There may be more than one position in the same class;

''Position allocation'', the initial official placing of a position in a class forming part of the position classification plan;

''Position classification plan'', the plan resulting from position allocations pertaining to the personal services of the counties;

''Position reallocation'', any subsequent official placing of a position in a class forming part of the position classification plan;

''Salary range'', a range of salaries from a specified minimum to a specified maximum amount as applied to a job group;

''Specification'', a description of the characteristic duties and requirements of a single class;

''Step-in-range'' or ''increment step'', one of the divisions of a salary range in a job group at which an employee is compensated.