Encontre esto en Answers.com. Se los recomiendo, es muy bueno y reliable.
Parece que si hay alguna pequenia diferencia.. habria que tener cuidado con el contexto.Tal vez al espaniol pueden ser los dos traducidos como contrato. Pero al ingles no.
Contract. An agreement between two or more parties, especially one that is written and enforceable by law
The writing or document containing such an agreement.
Traduccion. Contrato
Agreement.
A
meeting of minds with the understanding and acceptance of
reciprocal legal rights and duties as to particular actions or obligations, which the parties intend to exchange; a mutual assent to do or refrain from doing something; a contract.
The writing or document that records the meeting of the minds of the parties. An oral
compact between two parties who join together for a common purpose intending to change their rights and duties.
An agreement is not always synonymous with a contract because it might lack an essential element of a contract, such as
consideration.