Your question doesn't really tell us what you want to do.
An Excel sheet (worksheet) is part of an Excel Workbook which is saved as a file with an Excel extension such as .xls
If you want to link the contents of one cell in a worksheet in one workbook to a cell in another workbook, then do this:
Open the source workbook.
Select the cell containing the data you want to link to
Right-click and copy that cell
In the destination workbook, select the cell to hold the linked information
Right-click and Paste Special
In the Paste Special dialog box click the Paste Link button
You destination cell will show something like this:
When you close the source workbook the destination cell will include the full path name as well: