What does the union jack mean?

Question

What does the union jack mean?

Answer 1

What is usually called the "Union Jack" is actually the "Union Flag" --

the flag of the United Kingdom.  The "Union Jack" is identical in design,

but the term should be used only for a flag meant to fly from a ship's

"jack-staff."  (The design of a jack is, by definition, the same as the 1st

canton of the country's naval flag.  Britain is unique; the national flag

and the jack differ from each other in other countries.  The U.S. jack,

for example, is a blue field with 50 silver stars.)    

Answer 2

It represents the union of three countries:

England - the Red cross (Flag of St George)

Scotland - the white diagonal cross and the blue background (Flag of St Andrew)

Ireland - the Red Diagonal cross (Flag of St Patrick)

Wales was considered as part of England when the flag was created.

See:

http://www.woodlands-junior.kent.sch.uk/...