The vlookup function is useful when you have two tables, where both tables have a common identifier such as a primary key from a database table, and you want to add column to table 1 with data pulled from a matching row in table 2.
Example:
=IFERROR(VLOOKUP(A3,Sheet1!A:B,2,FALSE),"")
the VLOOKUP function is “wrapped” in an IFERROR function above so that any results where matches are not found will show blank instead of the Excel default of “#N/A”
A3 holds the common identifier (primary key) in table 1
Sheet1!A:B defines the table 2 area
2 is saying we want to fetch and display the value of the 2nd column of table 2
FALSE says we did not sort the common identifier (primary key) in table 2