It is an honour.
People who have worked exceptionally hard and performed exceptionally well a t some enterprise,be it medicine,sports,the arts,business,civil rights,charities can be nominated for an honour.
begins the explanation:
"An Investiture is a very special day when an individual who has been awarded an honour receives their award in person from The Queen or The Prince of Wales.
Around 20 Investitures are held in the Ballroom at Buckingham Palace each year. Another takes place at the Palace of Holyroodhouse in Edinburgh, and sometimes one more at Cardiff Castle in Wales.
Investitures are also occasionally held overseas, during a State visit by The Queen or a foreign visit by another member of the Royal Family.
Recipients can bring with them to the Investiture up to three friends or relations, who are invited to sit in the audience to witness the occasion.
At the start of the ceremony The Queen enters the room attended by two Gurkha orderly officers, a tradition begun by Queen Victoria in 1876.
Also on duty are members of The Queen's Body Guard of the Yeomen of the Guard, which was created by Henry VII in 1485. Music is provided by either a military band or an orchestra from the Purcell School of Music.
The Queen, or the member of the Royal Family holding the Investiture, remains standing throughout. Each Investiture takes about an hour.
After the National Anthem has been played either the Lord Chamberlain or the Lord Steward announces the name of each recipient and the achievement for which he or she is being honoured. The Queen then places the decoration on the person concerned before congratulating them on receiving the award.
Those who are to receive a knighthood (and who are therefore entitled to style themselves Sir), kneel on an Investiture stool before The Queen. She uses the sword that belonged to her father, King George VI, to dub the knight.
As well as receiving awards within one of the Orders of Chivalry, recipients may also attend to receive a decoration for gallantry such as the George Cross or The Queen's Gallantry Medal.
Occasionally an award for gallantry may be made posthumously, and in this case The Queen presents the decoration or medal to the recipient's next of kin at a private ceremony before the formal Investiture begins.
The Central Chancery of the Orders of Knighthood, which is a department of the Lord Chamberlain's Office, is responsible for the organisation of each Investiture.
The Central Chancery also organises the distribution of British insignia awarded by The Queen throughout the Commonwealth."
Knighthoods are explained on http://www.royal.gov.uk/output/page4877.asp
A knighthood (or a damehood, its female equivalent) is one of the highest honours an individual in the United Kingdom can achieve.
While in past centuries knighthood used to be awarded solely for military merit, today it recognises significant contributions to national life.
Recipients today range from actors to scientists, and from school head teachers to industrialists.
A knighthood cannot be bought and it carries no military obligations to the Sovereign.
The Queen (or a member of the Royal Family acting on her behalf) confers knighthood in Britain, either at a public Investiture or privately.
The ceremony involves the ceremonial dubbing of the knight by The Queen, and the presentation of insignia.
By tradition, clergy receiving a knighthood are not dubbed, as the use of a sword is thought inappropriate for their calling.
Foreign citizens occasionally receive honorary knighthoods; they are not dubbed, and they do not use the style 'Sir'.
Such knighthoods are conferred by The Queen, on the advice of the Foreign and Commonwealth Office, on those who have made an important contribution to relations between their country and Britain.
Foreign citizens given knighthoods over the years include Chancellor Kohl, President Mitterrand and Mayor Giuliani of New York.
The origins of knighthood are obscure, but they are said to date back to ancient Rome, where there was a knightly class Ordo Equestris (an order of mounted nobles).
Knighthood became an established military guild in many European countries, and it had certain characteristics: a would-be knight would undertake strict military training from boyhood, including some time as an assistant (an esquire) to a knight with whom he rode to war.
He would also have to prove himself worthy according to rules of chivalrous behaviour, such as 'faithfulness to his Saviour and his Sovereign', generosity, self-denial, bravery and skill at arms.
In addition, he would be expected to have the financial ability to support the honour of knighthood, so that he could provide himself with arms, armour, horses and the required number of armed followers to render military service to his Sovereign for a minimum period each year.
In former times, no person could be born a knight: even monarchs and their heirs had to be made knights.
Alfred knighted his grandson Athelstan; William I was knighted when he became king (although he had previously been knighted in Normandy); Edward III, Henry VII and Edward VI were all knighted, after coming to the throne, by one of their subjects.
The conferment of knighthood involved strict religious rites (encouraged by bishops who saw the necessity of protecting the Church, and of emphasising Christian ideals in order to temper the knights' ferocity), which included fasting, a vigil, bathing, confession and absolution before the ceremony took place.
The first and simplest method of knighting was that used on battlefields, when the candidate knelt before the Royal commander of the army and was 'stricken with the sword upon his back and shoulder' with some words such as 'Advances Chevalier au nom de Dieu'. (The action of touching the sword on the recipient's shoulder is known as dubbing.)
The second method involved greater ceremony, which could include the offering by the knight of his sword on the altar.
Although the monarch's 'lieutenants in the wars' and a few others of high birth could knight others, over the years successive Sovereigns began drastically to limit the power to confer knighthood - particularly Henry VIII.
Eventually, it became the custom for monarchs to confer all knighthoods personally, unless this was quite impracticable.
However, knighthoods were not necessarily sought after, as there were men who wanted to avoid an honour which compelled them (at great expense and personal inconvenience) to reinforce the Sovereign's armies.
The alternative to knighthood was the payment of a fine instead of military service, and kings such as Edward II, James I and Charles I found such fines a useful source of income for the crown (this practice of fining was abolished in Charles II's reign).
James I even instituted a new honour of baronetcy (a title which could be passed on to descendants) in 1611, so that he could raise money and valuable reinforcements for his army.
In extreme cases, when a knight was found guilty of treachery or treason, he could lose his honour by formal degradation - a public ceremony in which his accoutrements were taken off him.
In 1468, Sir Ralph Grey was taken to Doncaster where, being guilty of treason, his 'gold spurs were hewn from his heels while his sword and all his armour were broken'.
The last public degradation was in 1621 at Westminster Hall, when Sir Francis Mitchell was found guilty of 'grievous exactions' and had his spurs broken and thrown away, his belt cut and his sword broken over his head. Finally, he was pronounced to be 'no longer a Knight but Knave'.
Other more recent examples of degradation from honours are when Sir Roger Casement had his knighthood cancelled during the First World War for treason. He was later executed. In 1979 Sir Anthony Blunt, a former Surveyor of The Queen's pictures, also had his knighthood withdrawn for espionage.
Currently, a person may be stripped of his knighthood should he be convicted of a criminal offence by a Court of Justice.
In ceremony of knighting, the knight-elect kneels on a knighting-stool in front of The Queen, who then lays the sword blade on the knight's right and then left shoulder.
After he has been dubbed, the new knight stands up, and The Queen invests the knight with the insignia of the Order to which he has been appointed.
Contrary to popular belief, the words 'Arise, Sir ...' are not used."