//These are the acceptable paramaters. 
Sheet1!A1:B2 refers to the first two cells in the top two rows of Sheet1.
Sheet1!A:A refers to all the cells in the first column of Sheet1.
Sheet1!1:2 refers to the all the cells in the first two rows of Sheet1.
Sheet1!A5:A refers to all the cells of the first column of Sheet 1, from row 5 onward.
A1:B2 refers to the first two cells in the top two rows of the first visible sheet.
Sheet1 refers to all the cells in Sheet1.

You can also get all the rows and columns with "Sheet1" and then iterate over the data you want