what's the difference between the union flag and the union jack
Union Jack The Union Jack,[note 1][2][3] or Union Flag, is the national flag of the United Kingdom. The flag also has an official or semi-official status in some other Commonwealth realms; for example, it is, by parliamentary resolution, a ceremonial flag in Canada and known there as the Royal Union Flag.[4] Further, it is used as an official flag in some of the smaller British overseas territories. The Union Flag also appears in the canton (upper left-hand quarter) of the flags of several nations and territories that are former British possessions or dominions.