Q:

What is the default scope of worksheets and cells and range?

When you just type worksheets() what is the default scope ActiveWorkbook or ThisWorkbook? For those who do not know these distinctions they are extremely important especially in Excel 2013 when you want macros to run when you switch to different workbooks.

A:

In a standard module an unqualified Worksheets() will always reference the ActiveWorkbook. In the ThisWorkbook module, the implicit qualifier is Me and that will reference the containing workbook.
Likewise, an unqualified Range() or Cells() (or Rows()/Columns()) in a standard module will reference the ActiveSheet, but in a sheet code module the implicit qualifier is Me, and will reference the corresponding worksheet.
Unqualified...       Where              Implicit Qualifier
--------------       --------------     -------------------
Worksheets(),        ThisWorkbook       Containing workbook (Me)
Sheets()             Any other module   Active workbook (via [_Global])

Range(), Cells(),    Sheet module       Containing sheet (Me)
Rows(), Columns(),   Any other module   Active sheet (via [_Global])
Names()

The easy way to avoid having to remember any of this is to always fully qualify any Worksheets, Sheets, Range, Cells, or Names reference.
Qualify the member call with Me when referring to ThisWorkbook in that module's code-behind, or when referring to Sheet1 in that module's code-behind.

