An oral agreement can include forms of oral agreement and a written contract. A verbal agreement is made without a formal written documentation. While the agreement is there and understood in spoken words it’s more difficult to prove in court. There may be instances where the written contract is necessary, for example in sales or transfer of real state, in agreements related to marriage or divorce, etc. Without documentation of an agreement, it becomes a matter of who said this and that. Sometimes, there are family disputes because of verbal agreement, they want to avoid the awkwardness between family members or close friends because by requesting a written contract it makes it look like one party doesn’t trust the other. I’ve seen cases where family members agreed to buy a good and pay some amount of money for it for a certain period of time, however, it did not happen like that and the family went through a dispute that caused hiring lawyers. Cases like this do not end up in happy endings, so I would say to go with the written agreement is safer.