A national flag is a symbol of a country's identity and is typically composed of a design featuring a specific set of colors, shapes, and symbols. The most common type of national flag is the TRICOLOUR, which consists of three equal-sized horizontal stripes of different colors. An ENSIGN is a type of flag that is used to identify a ship or a military unit. Colors are an important part of a national flag, as they are often used to represent certain values or ideals.