Flags are everywhere. They are mainly associated with geographical regions, countries and nations, but if you look around you will find them as symbols of many other walks of life.
A flag is basically a piece of material that is flown from a mast or pole, but once you start adding coloring, designs and emblems to that piece of cloth you have a work of art.
The historical origin of flags dates back to around 1000 BC, when the Egyptians used primitive versions of flags - some were even made out of wood or metal. Flags were originally used for the purpose of identification or to signal to others. Although flags are still used for many of those reasons today, flags have also come to be used for much more.
Flags have also been important symbols on land as well as on sea. Ships started using flags at sea to signal to each other and to harbors, often to let them know they had an infectious or diseased crew aboard. Flags are still used today to let sailors know what weather conditions await at sea. The military also made use of flags to rally its troops. In military times, capturing an enemy's flag was considered an honorable seizure.
Although the most popular use of flags today is to identify the world's countries, the use of national flags didn't become commonplace until the 18th century. National flags are now used to identify each country and their symbolism.
When Mount Everest and the moon were conquered, and when new found lands were discovered, explorers would raise flags as signs of their being the first to tread these unchartered lands. Flags have also been used historically, many with negative consequences. For example, ancient pirates used flags decorated with the feared skull and crossbones emblem, and the Nazis used a flag decorated with a swastika.
Today, flags are still used to signify crucial events. For example, if you are offside in a soccer game, the linesman raises his flag, or when an auto race begins a flag is traditionally waved to start the race.
In fact, the numerous uses for flags and their examination have become so popular that the practice of 'vexillology', which means the academic study of flags, has been developed.