Meals are divided into courses, which refers to items served together at once. For example, soup and crackers are a course, as are a salad, dressing, and bread served together. There is usually a pause in between courses, and the parts of a meal are brought out in a specific order. For example, if you order dessert and a main dish — two examples of courses — your entrée will arrive before the dessert unless you specify you want a different order.
Full Course Meals
Full course meals are made up of three courses: an appetizer, main dish, and dessert. Also known as a three-course meal or a standard course meal, you will sometimes see restaurants offering a full menu with these three items.
You can add more courses to a full course meal. This will add to the course length, so a four-course dinner will include an appetizer, main dish, and dessert but also a fourth course — hors-d’oeuvres — served before the appetizer. If you choose a five-course dinner, you’ll get a four-course meal with a salad after the appetizer, before the main dish.
You can adapt the number of courses of a meal to suit your occasion. For example, if you’re planning a wedding reception, you will probably want a three-course or four-course meal, since that is standard. The same applies to wedding rehearsal dinners. Very formal dinners may include more courses.
In formal dining, a full-course dinner can consist of 5, 6, 8, 10, 12, or 16 courses, and, in its extreme form, has been known to have 21 courses. In these more formalized dining events, the courses are carefully planned to complement each other culinary wise. The courses are smaller and spread out over a long evening, up to three to even five hours. They follow conventions of menu planning that have been established over many years. Most courses (excluding some light courses such as sorbets) in the most formal full-course dinners are usually paired with a different wine, beer, liqueur, or other spirit.
https://en.wikipedia.org/wiki/Full-course_dinner
https://marynastevenson.co.za/2022/06/09/table-manners-are-truly-important/