The document discusses various modes of discharge of a contract, including: 1) By performance, where both parties fulfill their obligations under the contract. 2) By impossibility of performance, such as an agreement becoming impossible or unlawful to perform. 3) By agreement between the parties, through novation, alteration, rescission, remission, or waiver. 4) By operation of law, such as due to insolvency or the lapse of time under limitation laws. 5) By breach of contract, where a party fails to perform their obligations or makes performance impossible.