These terms describe who uses a flag and where. A civil flag is for private citizens, a state flag is for the government, and a war flag is for the military — while an ensign is the version flown on ships and a jack is a small flag at a ship's bow. "National flag" is the loose, everyday term for a country's main flag. Where a country uses one design for everything, all these labels point to the same flag.
Civil flag
A civil flag is the flag intended for use by private citizens and non-government organisations — the one you'd fly outside your house or business. In many countries it's identical to the main national flag. But where a country has more than one version, the civil flag is usually the plainer one, without a coat of arms or state emblem. Spain is the standard example: the civil flag is simply red-yellow-red.
plain, for citizens
with the coat of arms
State flag
A state flag is the version used by the government and its official institutions — on ministries, embassies and official documents. It often adds a coat of arms or emblem that the civil flag omits, precisely to signal official authority. Spain, Peru, Bolivia and several other countries maintain this civil/state split.
War flag (military flag)
A war flag, or military flag, is the version used by a country's armed forces on land. Many nations simply use their national flag, but some have historically flown a distinct military design. It's the third member of the classic trio — civil, state and war — that flag experts use to classify a country's flags.
Ensigns — flags at sea
An ensign is a flag flown by ships to show their nationality, usually at the stern (the back). Maritime tradition mirrors the civil/state/war split on land, so a country can have a civil ensign for merchant ships, a state ensign for government vessels, and a war (naval) ensign for its navy. The United Kingdom's Red, Blue and White Ensigns are the classic set, and Japan's Rising Sun naval ensign differs from its national flag — examples we show in why some countries have more than one flag.
Jack — the flag at the bow
A jack is a small flag flown from a staff at the bow (the front) of a ship, separate from the ensign at the stern. It's a minor term with a famous legacy: the UK's national flag is nicknamed the "Union Jack" precisely because of its use as a maritime jack.
How the terms fit together
The clearest way to see it is as a grid: who uses the flag across the top, and where it's used down the side.
| Used on… | Civil (private citizens) | State (government) | War (military) |
|---|---|---|---|
| Land (a "flag") | Civil flag | State flag | War flag |
| Sea (an "ensign") | Civil ensign | State ensign | Naval ensign |
Most countries fill this whole grid with a single design — one flag for every box. Countries with a richer flag tradition give some boxes their own distinct version, which is how one nation ends up with several official flags.
The terminology is country-specific
Finally, a caution: there's no single global rulebook that forces every country to use these words the same way. One nation's "state flag" might be another's "national flag," and some countries don't make any of these distinctions at all. Flag scholars use a shared set of symbols to chart the different uses, but the most reliable guide is always a given country's own official definitions — which is the approach we take across the Flag Explorer.
Frequently asked questions
What is the difference between a national flag and a civil flag?
"National flag" is the broad term for a country's main flag; a "civil flag" is specifically the version for private citizens, often the plainer design where a country has more than one.
What is a state flag?
The version used by the government and its institutions, often adding a coat of arms the civil flag leaves off.
What is a flag ensign?
A flag flown by ships (usually at the stern) to show nationality — with civil, state and naval ensigns for different vessels.
What is a jack on a flag?
A small flag at a ship's bow. The UK's "Union Jack" is named after this maritime use.
Is there a global standard for flag terminology?
No — usage varies by country, so each nation's own official definitions matter most.