Cells, or columns, can be accessed by index or by column name. Your former example retrieves the cell by name, the latter by index.

the .Cell.item(0) retrieves the first cell in the row (returning some kind of cell object); .Value gets the value object of that cell; .ToString converts the resultant value to a string.

note that there is the chance that you can get a total of 5 errors on that single line (e.g. what if the .Value of the cell is Nothing?).