Mississippi Code Title 7. Executive Department § 7-17-11

(a) Agency -- the principal administrative organization of state government as defined in Section 25-9-107(d), headed by an executive director or such other official as prescribed by statute;

(b) Office -- the principal organization of an agency; whenever the term “division” or any other term appears to denote the principal organization of a department, it shall mean “office” for purposes of this section;

(c) Bureau -- the principal organization of an office;

(d) Division -- the principal organization of a bureau;

(e) Branch -- the principal organization of a division;

(f) Section -- the principal organization of a branch;

(g) Unit -- the principal organization of a section;

(h) Advisory board -- a body appointed to function on a continuing basis to study and recommend solutions and policy alternatives to problems arising in a specific agency or program of state government.