Filling in the essential sections of the contract
Signing a subcontract

The preamble to a contract explains the contract, and therefore the commitment of the parties.

This involves recalling the contractual environment, for example, the customer's needs and the subcontractor's particular skills, and the history of relations between the contracting parties.

The contract itself defines the rights and obligations of the parties.

Its purpose is to facilitate interpretation of the parties' intentions, in the event of difficulty.