73 Pa. Stat. § 502
The following words and phrases when used in this act shall have the meanings given to them in this section unless the context clearly indicates otherwise:
"Billing period." A payment cycle agreed to by the parties or, in the absence of an agreement, the calendar month within which work is performed.
"Construction contract." An agreement, whether written or oral, to perform work on any real property located within this Commonwealth.
"Contractor." A person authorized or engaged by an owner to improve real property.
"Deficiency item." Work performed but which the owner, the contractor or the inspector will not certify as being completed according to the specifications of a construction contract.
"Delivery." Transmittal to an addressee, including, but not limited to, delivery by first class or registered mail, hand delivery or transmission by facsimile machine. Mail, properly addressed, shall be deemed delivered three days from the day it was sent.
"Improve." To design, effect, alter, provide professional or skilled services, repair or demolish any improvement upon, connected with, or on or beneath the surface of any real property, to excavate, clear, grade, fill or landscape any real property, to construct driveways and private roadways, to furnish materials, including trees and shrubbery for any of these purposes, or to perform any labor upon improvements.
"Improvement."
"Inspector." The contractor or a person authorized or engaged by the owner to inspect the work performed pursuant to a construction contract to determine whether the work completed is in compliance with the construction contract.
"Owner." A person who has an interest in the real property that is improved and who ordered the improvement to be made. The term includes successors in interest of the owner and agents of the owner acting with their authority.
"Person." A corporation, partnership, business trust, other association, estate, trust foundation or a natural individual.
"Real property." Real estate that is improved, including lands, leaseholds, tenements and hereditaments, and improvements placed thereon.
"Subcontractor." A person who has contracted to furnish labor or materials to, or has performed labor for, a contractor or another subcontractor in connection with a contract to improve real property.
73 P.S. § 502