The Full House highlights the submission of a Singles strategy in Sudoku. This occurs when a house, either row, column, or block, has only one empty
cell left as in its filled all other cells. If it happens to be the last missing digit in the entire puzzle, it is commonly known as The Last Digit.
Sometimes, is referred to as The Last Digit
Example 1:
In Block 8 (B8), only R9C6 remains empty. Since the numbers 1-9 are already present except for 6, R9C6 must be 6.
Example 2:
For Row 5 (R5), all digits except 1 are filled. Thus, 1 must occupy the sole empty cell in R5.