National flag is one of the symbols of a country. It is traditionally flown by a government and its institutions but it can be flow by citizens too. National flags that are used on land have three different types as well as national flags for use at sea. Many countries use same flag for each of these purposes.
Flags evolved from military standards that were used in battles so fighters could differentiate friends from foes. Age of sail that began in 17th century introduced using flags as indication of the country of origin. From these flags developed national flags. Nationalist sentiment becomes noticeably stronger in 18th century and at that times many countries started using national flags that were often designed from older war flags.
National flags that are used on land can be divided in three groups: state flags, civil flags and war flags. Flags that are used by government agencies are state flags. Civil flags can be flown by anyone. War flags, or military flags, are used by armies and other military organizations. These flags can be different from each other for one country but more often they are same or similar. When they are different, in most cases civil flag has same colors as state flag but without coat of arms.
National flag used on a ship is called ensign and indicates nationality of the ship. There are also three types of ensign for flags at sea too: state ensign that is flown by government ships, civil ensign that is flown on ships that are in civil property and war ensign on naval vessels. If flags are used on aircrafts and the land vehicles they are painted.
When the national flag is displayed, there are protocols which govern how that is done. For instance: displaying of a national flag with other flags follows certain rules. National flag is always hoisted first and lowered last. If other flags are also national flags, they should be approximately same size and flown at an equal height but national flag of the host should be at the place of honor. If there is odd number of flagstaffs it should be in the middle and if there is even number of flags it should be flown on the far right or the far left flagstaff. If other flags are not national flags, national flag is flown on a separate flagstaff higher than other flags or in the position of honor. When all the flags are flown on the same flagstaff, national flag is flown on the top of the flagstaff, above all other flags. If a national flag is flown with other flag in a way that their staffs are crossed, national flag is placed on the viewer’s left and its staff must be in front of the staff of the other flag. If flown in procession with other flags, national flag should be on the right side of the procession or in place of honor when there is a row of flags.