In this case "id" is a named range = B4 (which contains the lookup value), and "data" is a named range = B8:E107 (the data in the table). The number 3 indicates the 3rd column in the table (last name) and FALSE is supplied to force an exact match.
In "exact match mode" VLOOKUP will check every value in the first column of the supplied table for the lookup value. If it finds an exact match, VLOOKUP will return a value from the same row, using the supplied column number. If no exact match is found, VLOOKUP will return the #N/A error.
Note: it's important to require an exact match using FALSE or 0 for the last argument, which is called "range_lookup"). Otherwise, VLOOKUP might return an incorrect result.