Box
Any one of the 3x3 sub-divisions of the 9x9 grid, usually outlined in a thicker border to distinguish the nine boxes in the grid. Also known as a block.
Candidates
The numbers that could potentially be entered into an individual cell, determined by which numbers aren't already in any row, cell or box that the cell belongs to.
Column
Any of the nine vertical stacks of cells within the grid.
Givens
The numbers "given" to you as starter numbers when you start the puzzle. Usually 32 numbers or less under the standards set by Nikoli.
Grid
The playing area for a sudoku puzzle. Normally 9x9 cells in dimension.
House
A collective term for a row, column or box.
Row
Any of the horizontal lines of cells within the grid.