: là một sự thỏa thuận có ít nhất hai người, Hợp đồng song phương có quy định rõ ràng nhiệm vụ của hai bên. Ưu điểm: Hai bên hiểu rõ những gì đã thỏa thuận.
: is an agreement of at least two people, a bilateral contract has clearly defined the duties of the two parties.Pros:Both sides clearly understand what was agreed.
: An agreement with at least two people, a bilateral contract with clearly defined duties of both parties. Advantage: Both parties understood what was agreed.