Answer
The Line of Succession to the Throne of the United Kingdom of Great Britain and Northern Ireland is determined by a piece of Legislation called the Act of Settlement of 1701.
Broadly speaking, the current monarch is followed by their own, legitimate children.
Until 2013, males were given preference to females and older sons of the monarch came before younger sons and their offspring.
This was changed in anticipation of the birth of a baby by The Duchess of Cambridge so that gender would not be a deciding factor in the baby's place in the succession.
Anyone whose parents were not married when they were born are excluded.
The current order is:
Monarch Her Majesty Queen Elizabeth II - born 1926
Heir Apparent (next in line) His Royal Highness The Prince Charles, Prince of Wales, eldest son of Queen Elizabeth II, born 1948, then
His Royal Highness The Duke of Cambridge (Prince William of Wales), eldest son of Prince Charles, born 1982 then,
Prince George of Cambridge, son of Prince William, born 22 July 2013, then
His Royal Highness Prince Henry of Wales, second son of Prince Charles, born 1984, then
His Royal Highness The Prince Andrew, Duke of York, second son of Queen Elizabeth II, born 1960, then
Her Royal Highness Princess Beatrice of York, daughter of Prince Andrew, born 1988, then
Her Royal Highness Princess Eugenie of York, daughter of Prince Andrew, born 1990, then
His Royal Highness The Prince Edward, Earl of Wessex, third son of Queen Elizabeth II, born 1964, then
His Royal Highness The Prince James of Wessex, Viscount Severn, son of Prince Edward, born 2007, then
Her Royal Highness Princess Louise of Wessex, daughter of Prince Edward, born 2003, then
Her Royal Highness The Princess Anne, Princess Royal, daughter of Queen Elizabeth II, born 1950, then
Peter Phillips, son of Princess Anne, born 1977, then
Savannah Phillips, daughter of Peter Phillips, then
Isla Phillips, daughter of Peter Phillips, then
Zara Phillips, daughter of Princess Anne, born 1981.
The Line then passes to descendants of Queen Elizabeth's late sister, The Princess Margaret.
After King Charles, Prince William is next in line for the British throne. King Charles is Prince William's father.
The next female in line for the throne is Princess Beatrice of York. She is currently fifth in line for the throne assuming that Prince William and Kate do not have a daughter.
Constitutionally Prince Charles is currently next in line to the British throne. Whether he succeeds the Queen is his choice.
You haven't said which throne, but if you mean the British monarchy, next in line after Queen Elizabeth II is her son, Prince Charles, and next in line after Prince Charles is his oldest son, Prince William. There are a whole lot of more people in line, too, after them.
Constitutionally Prince Charles is currently next in line to the British throne. Whether he succeeds the Queen is his choice.
Yes, he could theoretically decline his title as King. At that point, Prince William is next in line to the throne.
Yes, Charles, Prince of Wales, is next in the line of succession to the British throne.
The next in line for the British throne is Prince Charles, the son of Queen Elizabeth. If anything should happen to him, Prince William would be next in line for the throne. Since these are men and will be a king, not a queen, obviously, there will be not be another queen in England for the foreseeable future. The next female in the line of succession would be HRH Princess Beatrice of York (number 5 in the line of succession).
Prince Andrew, Duke of York, is fourth in line to the British throne. Prince Edward, Earl of Wessex, is seventh in line to the British throne.
Princess Viktoria.
The word is heir.
Prince Henry of Wales