Sudoku (数独 sūdoku, digit-single) - is a logic-based, combinatorial number-placement puzzle. The objective is to fill a 9×9 grid with digits so that each column, each row, and each of the nine 3×3 subgrids that compose the grid (also called "boxes", "blocks", or "regions") contains all of the digits from 1 to 9.

Jigsaw Sudoku:

The rules of Jigsaw Sudoku are similar to standard Sudoku since you must place each of the numbers 1 to 9 (or 1 to whatever the size of the puzzle is) into each of the rows and columns. However, whereas standard Sudoku also has rectangular boxes that must each contain every number, in Jigsaw Sudoku these boxes are replaced by different bold-lined shapes that must each contain every number instead.

Killer Sudoku:

Killer Sudoku puzzles include all the rules of regular Sudoku but add in dashed-line 'cages' which must sum to given values. Killer Sudoku is also sometimes known as Sumdoku, Mathdoku or Addoku. The name 'Killer' Sudoku arises because of the wicked twist on the standard Sudoku puzzle, since you must not only place each of the numbers 1 to 9 (or 1 to the size of the puzzle) into each of the rows, columns, and bold-lined 3x3 (or other sizes) boxes but you must also place the numbers into each dashed-line cage so that they add up to its given total - and without repeating a digit in a dashed-line cage.