A question about Excel.Save()

Aspose.Cells Product Family
1

I invoke the Excel.Save(String Filename) to create and save the specified file to disk. After that, I do the below.

FileStream fs = new FileStream(fileName, FileMode.Open);

then I get the fs.length.

In other way, I call Excel.Save( System.IO.Stream stream , Aspose.Excel.FileFormatType fileFormatType ).

stream.length<fs.length, Why they are not the same?

2

What’s the difference of these two length?