Answer:
Oral communication involves the transmission of information using spoken words. In oral communication, the pace of delivery of such information is speedy and therefore, there might be a case of misunderstanding of such message. This form of communication is mostly considered as informal.
An example of oral communication is the delivery of a speech in a school debate.
Written communication on the other hand involves the exchange of message or information in a printed or written form. This method of communication is considered formal since proper documentation for referential purposes can be done.
An example of written communication is sending an email to a colleague at work.
Both communication forms are great in their own usages, but the oral communication is seen as prior as this is the oldest form of communication. Also, one tends to learn to speak before they write.
