bawl definition: To bawl is defined as to cry or wail loudly. (verb) An example of bawl is to sob loudly upon hearing bad news. ...
Legality: A contract is a legal document and a PO is a commercial document. To elaborate, a PO is an offer from the buyer to the supplier. If accepted by the supplier (within a reasonable timeframe) the PO becomes a contract. Logically, this PO will have zero value if it's not accepted by the supplier.
The essential difference between an agreement and a contract is that typically an agreement will only modify a contract that is already in place but does not place an obligation on either one of the parties to provide consideration to the other party, which a contract requires.