The following words, terms and phrases, when used in this division, shall have the meanings ascribed to them in this section, except where the context clearly indicates a different meaning:

bid means a formal written and sealed response to a formal advertisement for specified requirements.

bidder means an offeror who submits a bid or proposal to the city.

Blanket purchase order means a continuing purchase order designed to capture cumulative transactions to reduce the administrative costs of placing recurrent orders with an established vendor.

Construction means and includes all improvements to real property.

Contract means a mutually binding legal relationship between the city and another party obligating the other party to furnish supplies, services or construction to the city and the city to pay for them. It includes all types of commitments that obligate the city to an expenditure of funds, and that, except as specifically provided in this division, are in writing. Contracts include bilateral instruments, purchase orders, contract modifications and orders under blanket purchase orders.

proposal means an offer submitted to the city in response to a city request for proposals which permits persons to offer, at least in part, the method or manner of contract performance or to specify alternatives to the stated city requirements.

Purchase order means a unilateral instrument issued by the city ordering supplies, services, or construction which becomes a contract by the other party through formal acceptance or by performance.

services means and includes all personal and nonpersonal services, utilities, insurance, leases for real and personal property, rental, repairs, and maintenance of real or personal property. The term shall not include professional services.