What does the Union Jack symbolize?

Answer 1

Jacks are additional national flags flown by warships (and certain other vessels) at the head of the ship. These are usually flown while not underway and when the ship is dressed on special occasions. Jacks in the Royal Navy must be run up when the first line is ashore when coming alongside.

Apparently the British navy started this.

Answer 2

The Union Jack or more properly, the Union Flag, is the flag of the United Kingdom of Great Britain and Northern Ireland. The flag in its present form was adopted in 1801. The red horizontal cross is the Cross of St. George which represents England (and Wales which is considered part of England for govermental purposes). The white "X" shaped cross on the blue background is the Cross of St. Andrew and was the former flag of Scotland. The red "X" shaped cross is the Cross of St. Patrick and represents Ireland.

From 1606-1801 the Union Flag had only St George's and St. Andrew's crosses.

Answer 3

Scotland, England and Island flags are combined together to make the union jack

Answer 4

It means that Australia was once a member of the British Empire.