An escrow agreement is, by definition, an ancillary agreement as it acts as a guarantee for the main agreement.
In financial terms, an escrow agreement is a guarantee deposit adopted in international sales transactions by activating an escrow account used in connection with the flow of goods at the basis of the agreement between the parties.
Escrow Agreement Subjects
The person who deposits the asset object of the escrow agreement
The person who derives advantage and guarantee from the deposit
Depositary or Escrow Agent
A third person, a neutral middleman between Depositor and the Beneficiary, who holds the assets object of the agreement in trust and delivers them to the Beneficiary once the specified conditions of the contract are met (or otherwise returns them to the Depositor).