V-LOOK UP in Excel

One of the most critical functions in an Excel sheet is a V-look up. It functions similar to a left join in SQL.

Imagine having two excel sheets in a workbook or two different sheets in two different workbooks. The value of a certain column in the first worksheet could be obtained by referencing the value of that column in the second sheet. How would you do it ? Simple ..just like the below !

When comparing two column values to check if elements in Column A are present in Column B.

The above formula can be customized at per the problem statement.