Except as otherwise provided by this chapter and Chapters 2156, 2157, and 2158:
(1) "Goods" means supplies, materials, or equipment.
(2) "Service" means the furnishing of skilled or unskilled labor or professional work, but does not include a:
(A) professional service subject to Subchapter A, Chapter 2254;
(B) service of a state agency employee;
(C) consulting service or service of a consultant as defined by Subchapter B, Chapter 2254; or
(D) service of a public utility.