Hello and welcome to this course on the Naked Pair Technique!
This technique is similar to the blocked candidate technique, so if you have followed the previous lesson well, this one should be easy to understand.
The rule is simple, if there are two cells in a house that only have 2 candidates, you can eliminate those 2 candidates from all the other cells in that house.
Let's look at the grid below. If we look closely at row R8, we can see that in cell number 8, the two cells in the house have only two possible candidates, the number 2 and the number 8.
Therefore, it is impossible for cell R8-C4 to have 2 or 6 as candidates. Therefore, we can safely remove these candidates from this cell.