What does parol evidence refer to?

Parol evidence refers specifically to oral or verbal evidence communicated outside of the written contract or document being considered in a legal context. In legal terms, parol evidence is often discussed in relation to the "parol evidence rule," which generally prohibits the introduction of oral statements or agreements made prior to or at the time of signing a contract if they contradict or add to the written terms of that contract. The reason this concept is important is that it preserves the integrity of written agreements by preventing parties from claiming that verbal statements made previously should alter the understanding of the written terms.

The other options mentioned do not align with the legal definition of parol evidence. Written statements during a trial pertain to documents or transcripts that are recorded but do not reflect oral exchanges. Documents submitted as evidence can include a variety of written materials but do not specifically refer to oral or verbal evidence. Testimony from expert witnesses involves providing specialized knowledge or opinions based on expertise, which is different from the concept of parol evidence that deals explicitly with oral information outside the written documentation.