Final answer:
The parol evidence rule is a legal principle that states that a written contract cannot be changed by oral evidence.
Step-by-step explanation:
The parol evidence rule is a legal principle that states that a written contract cannot be changed by oral evidence.
This means that once parties have signed a written contract, any prior oral or written agreements that were not included in the final written document are generally not admissible as evidence in court to contradict or vary the terms of the written contract.
For example, if two parties have a written contract that states one thing, but one-party claims that there were additional verbal agreements or understandings that are not reflected in the written contract, the parol evidence rule would generally prevent the court from considering that evidence to change the terms of the written contract.