An oral report may be delivered around a small table with just a few listerners or in a large auditorium to hundreds of people.
Informal oral reports are generally characterized by small-group settings with a high degree of audience interaction and a relaxed manner of delivery and dress. An informal oral report might be an impromptu presentation. Informal oral presentations can foster the free exchange of ideas and be important for producing action items.
A formal oral report is distinguished by its adherence to an agreed-upon format or outline. Formal oral reports are usually prepared well in advance of presentation and are therefore well rehearsed. Your manner of delivery is extremely important in a formal oral report situation. Audience interaction is generally limited to the question and answer period at the conclusion of your report.
Formal oral reports may follow an outline similar to the parts of any formal written report and may be presented to an audience of one's peers or to an interested general or mixed audience in a setting such as a large auditorium or hall. However, the size of a room or an audience does not solely define a formal situation. Formal oral reports may also include presentations to small in-house groups of managers or academic committees, for example.
Presenting effective formal oral reports is an important means of establishing and maintaining your credentials and authority within a field or within an organization.
For an example of a formal oral report, see section Example of Materials for an Oral Presentation: Design Review.