Great Britain is the name of the island which is made up of England, Scotland, Wales, whereas the British Isles is the geographical name of all the islands off the north-west coast of the European continent. In everyday speech "Britain" is used to mean the United Kingdom.
The flag of the United Kingdom, known as the Union Jack, is made up of three crosses. The upright red cross on a white background is the cross of the 1st George, the patron saint of England. The white diagonal cross on a blue background is the cross of St. Andrew, the patron saint of Scotland, The red diagonal cross on a white background is the cross of St. Patrick, the patron saint of Ireland.
The Welsh flag, called the Welsh dragon, represents a red dragon on a white and green background.
St. George's Day falls on 23 April and is regarded as England's national day. On this day some patriotic Englishmen wear a rose pinned to their jackets'. A red rose is the national emblem of England from the time of the Wars of the Roses (15th century).
St. Andrew's Day (the 30th of November) is regarded as Scotland's national day. On this day some Scotsmen wear a thistle in their buttonhole. As a national emblem of Scotland, thistle apparently first used in the 15th century as a symbol of defence. The Order of the Thistle is one of the highest orders of knighthood. It was founded in 1687, and is mainly given to Scottish noblemen (limited to 16 in number).
St. Patrick's Day (the 17th of March) is considered as a national day in Northern Ireland and an official bank holiday there. The national emblem of Ireland is shamrock. According to legend, it was the plant chosen by St. Patrick to illustrate the Christian doctrine of the Trinity to the Irish.
St. David's Day (the 1st of March) is the church festival of St. David, a 6th-century monk and bishop, the patron saint of Wales. The day is regarded as the national holiday of Wales, although it is not an official bank holiday.
On this day, however, many Welshmen wear either a yellow daffodil or a leek pinned to their jackets, as both plants are traditionally regarded as national emblems of Wales.
In the Royal Arms three lions symbolize England, a lion rampant — Scotland, and a harp — Ireland. The whole is encircled and is supported by a lion and a unicorn. The lion has been used as a symbol of national strength and of the British monarchy for many centuries. The unicorn, a mythical animal that looks like a horse with a long straight horn, has appeared on the Scottish and British royal coats of arms for many centuries, and is a symbol of purity.