Some countries use a single flag design to serve as the national flag in all contexts of use. Others use multiple flags that serve as the national flag, depending on context, such as who is flying the national flag and where. The six basic contexts of use and potential variants of a national flag are:
- Civil flag - Flown by citizens on land.
- State flag - Flown on public buildings.
- War flag - Flown on military buildings.
- Civil ensign - Flown on private vessels; fishing craft, cruise ships, yachts, etc.
- State ensign - Flown on unarmed government vessels.
- Naval ensign - Flown on warships.
Badge - A coat of arms or simple heraldic symbol.
Canton - Any quarter of a flag, but commonly means the upper hoist quarter, such as the field of stars in the flag of the United States or the Union Jack in the Australian Flag.
Charge - A figure or symbol appearing in the field of a flag.
Emblem - A device often used as a charge on a flag. It may be heraldic in origin or modern, for example the maple leaf on the Canadian Flag.
Field - The background of a flag; the color behind the charges
Fimbriation - A narrow edging or border, often in white or gold, on a flag to separate two other colors. For example the white and gold lines of the South African Flag.
Finial - A decorative or protective cap atop the flagpole. Often shaped like a sphere, but can also be a shape with heraldic significance, such as a spear or an eagle. Sometimes referred to as a capper.
Fly - The half or edge of a flag farthest away from the flagpole. This term also sometimes refers to the horizontal length of a flag.
Heading - A piece of loose fabric running along the hoist for attaching a flag to its rope.
Hoist - The half or edge of a flag nearest to the flagpole. This term also sometimes refers to the vertical dimension of a flag.
Length - The span of a flag along the side at right angles to the flagpole.
Width or breadth - The span of a flag down the side parallel to the flagpole.
Banderole or bannerol - A small flag or streamer carried on the lance of a knight, or a long narrow flag flown from the mast-head of a ship
Bunting - Strong, coarse cloth used to make flags. Can also refer to a string of small festive flags
Burgee - A distinguishing flag of a recreational boating organisation, which commonly has the shape of a pennant
Canton - The top left quarter of a flag, also known as the first quarter or upper hoist. It is the position of honour on a flag
Civil ensign, merchant flag, or merchant ensign - A version of a national flag that is flown on civil ships to denote their nationality.
Courtesy flag or courtesy ensign - A flag that is flown on a visiting ship in foreign waters as a sign of respect for the foreign nation.
Ensign - The flag of any ship or military unit, or, generically, a synonym for any kind of flag. On ships, an ensign is normally flown at the stern.
Field - The background of a flag
Flag mast - A free-standing pole used for flying of flags. Often also used to describe a flagpole equipped with a yardarm and gaff
Fly - That portion of a flag furthest from the staff. This term also sometimes refers to the horizontal length of a flag.
Gaff - A spar set diagonally on the after side of a mast or flagpole
Half-mast - The flying of the flag below the top of a flagpole to indicate mourning
Halyard - The rope used to raise or lower a flag
Heraldry - The practice of designing signs involving symbols and devices on shields and flags as a means of identification, according to specific design protocols. Probably dates back to the 12th century, when warriors and jousters began wearing helmets that covered their faces, thereby obscuring their identity
Hoist - The half of a flag closest to the staff. Also to raise a flag
House flag - Generally, a flag flown by a trading or pleasure craft, identifying the company or person to which it belongs, but which may also be flown on buildings and vehicles
Jack - Originally, a national flag that was flown from the bow of a ship from the jack staff. Through custom, the Union Flag of the United Kingdom came to be known as the Union Jack
Peak - The tip of a gaff or flagpole
Roundel - A round decorative or identifying symbol, such as that used by the Royal Australian Air Force on its aircraft
Shield - A shield-shaped badge used in heraldry and often applied in the field of a flag
Staff - A short pole on which a flag is flown, for example, an ensign staff
Standard - Originally the banner of an important noble or member of a royal house. Now generally used to describe the banner of a head of state, for example the Royal Standard is the personal flag of The Queen in the United Kingdom
Weft - A nautical term meaning to tie a knot. In terms of a flag; tie the knot close to the head to leave the fly loose. This is the correct way to use a flag to signal distress. Inverting a flag went out of fashion in 1872 and is a sign of disrespect.
Yardarm - Sometimes called a cross arm. Either end of a yard