A contract can be discharged through several modes, including by agreement between the parties, operation of law, breach of contract terms, performance, or impossibility of performance. The key modes of discharge discussed in the document are discharge by agreement such as novation (replacing one contract with another), alteration (changing contract terms), rescission (cancellation), or remission (accepting partial performance). A contract is also discharged when the obligations are fully performed or made impossible to perform. Breach of contract terms by either party can lead to remedies for the injured party such as cancellation, restitution, specific performance, injunctions, or damages.