: Combine means first file  data is first then at end of the first
: file data second file data will be append but only one header  in
: the new file (either from first file or the second one doesn't
: matter because they both have same headers).

Okay. Let's describe the data. Does the script have to locate
the data or is it in a named or fixed range?
Both files  have same column name and same values accept one has less data

If the script has to locate the data in each sheet, does the
range of cells ever contain empty cells?
No. Also there is only one sheet  in both file which contains data

Will it ever contain empty cells in the future?
No

How do we find the header in the second file? Is it always in
a certain row? At the top of the data? Is it in just one row or
many? Is it a named range?
At the top of the data, first row in both file and just one row