Answer
Under Article 1157 of the Civil Code, obligations arise from five sources: (1) law; (2) contracts; (3) quasi-contracts; (4) acts or omissions punished by law (delicts — the civil liability arising from a crime); and (5) quasi-delicts (fault or negligence causing damage where there is no pre-existing contract between the parties).
An obligation is a juridical necessity to give, to do, or not to do. The source of the obligation matters because it determines the rules that govern it — an obligation from a contract is governed by the stipulations of the parties and the law on contracts, while one from a quasi-delict is governed by the rules on torts.
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