41 U.S.C. § 4101
Definitions
In this chapter:
(1) Delivery order contract.—
The term “delivery order contract” means a contract for property that—
(A)
does not procure or specify a firm quantity of property (other than a minimum or maximum quantity); and
(B)
provides for the issuance of orders for the delivery of property during the period of the contract.
(2) Task order contract.—
The term “task order contract” means a contract for services that—
(A)
does not procure or specify a firm quantity of services (other than a minimum or maximum quantity); and
(B)
provides for the issuance of orders for the performance of tasks during the period of the contract.
( Pub. L. 111–350, § 3 , Jan. 4, 2011 , 124 Stat. 3778 .)