Does every country have its own flag?

Every country has a national flag, including the United States. Flags date back to around 1000 B.C.E., when the Egyptians used primitive versions of flagssome were even made out of wood or metalto identify themselves and to signal to others. Ships started using flags at sea to signal to each other and to harbors, often to let them know they had a 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. During the ancient wars, capturing an enemy's flag was considered an honorable seizure. Today, the most popular use of flags is to identify the world's countries and their symbolism, which became commonplace in the 1700s. When new lands are discoveredand, for example when Mount Everest and the Moon were conqueredexplorers raise their country's flag as a sign of their being the first to set foot on these unchartered lands.