There are five different types of flight plans, all of which govern every aspect of aviation. As well as the previously mentioned VFR (Visual Flight Rules) and IFR (Instrument Flight Rules), the third (of the five) type of flight plan that governs civilian aviation is an International Flight Plan. While it falls under a similar category as an IFR flight plan, as it involves leaving and entering the airspace of different aviation authorities, it is more complicated and involved and is usually filed in advance of the flight being undertaken.
The remaining types of flight plans are both military and are usually only taught to pilots who are serving with the armed forces. The first is a Defense VFR (Visual Flight Rules) plan which is filed with the relevant military aviation authority and is filed in the same way that a civilian plan would be and the second, and last type of flight plan is a Composite Plan. This is a combination IFR and VFR plan and is usually used, and filed by, military pilots for long-range missions and flights.