This blog attempts to provide a new sudoku everyday and explain Solving Techniques.
Very similar to naked pairs but here we have 3 possible numbers for 3 cells. When we look at the image below, in box 5 and column 6, we have 1,2,3 as possible numbers for the 3 cells, R4C6,R5C6,R6C6, which have been circled. The buddy cell to all thes e3 cells is highlighted in yellow which is R2C6.
Hence 3 is eliminated from R2C6 and we have only the number 5 as a possibility for R2C6.