A contract is an agreement between parties that is legally enforceable. A simple "agreement" is an arrangement between the parties which may or may not contain the necessary elements to be enforceable before a court of law.
In Simple Words:
A Contract is enforceable by law while an Agreement is not enforceable by law.
A valid contract must contain the ten valid elements which are:
· Offer and Acceptance
· Intention to Create Legal Relations
· Lawful Consideration
. Capacity of Parties
· Free Consent
. Lawful Object
· Writing and Registration
· Certainty
· Possibility of Performance
. Not Expressly Declared Void