An excursion is a trip by a group of people, usually made for leisure, education, or physical purposes.
Public transportation companies issue reduced price excursion tickets to attract business of this type.
Short excursions for education or for observations of natural phenomena are called field trips.
One-day educational field studies are often made by classes as extracurricular exercises, e.g. to visit a natural or geographical feature.
twrd The term is also used for short military movements into foreign territory, without a formal announcement of war.