What does the union jack look like and what does it symbolize

The "Union Jack" or "Union Flag" is a composite design made up of three different national symbols. The cross represented in each flag is named after the patron saint of each country: St. George, patron saint of England, St. Andrew, patron saint of Scotland and St. Patrick, patron saint of Ireland.The first step taken in the creation of the flag of Great Britain was on 12th April 1606. When King James VI of Scotland became king of England (King James I) it was decided that the union of the two realms under one king should be represented symbolically by a new flag. Originally It consisted in the red cross of England superimposed on the white cross of Scotland on the blue background of the Scottish flag.