Each workbook that you create in Excel can be saved with a unique, meaningful name. Filenames can contain up to 256 characters and include both uppercase and lowercase letters, spaces, and punctuation. However, just because you can use up to 256 characters doesn't mean that each filename should be a long, rambling sentence. Filenames that are too long are almost as frustrating as filenames that are too short! Try to use as few words as possible to name your workbooks.
Check with your co-workers or network administrator to determine whether your company has adopted naming standards for files. For example, filenames might include a departmental name, the project title, or the year.
If you're using Excel in the office or you're going to share your files with others, make sure that everyone is using a version of Excel (and Windows) that supports long filenames. Excel for Office 95, Excel 97, Excel 2000, Excel 2002, Excel 2003, and Excel XP all support long filenames. If you're working with an earlier version of Excel , a long filename is truncated and contains a tilde (~) character at the end, such as LEGALDE~.
You might have noticed when you saved the practice file that Excel assigned a period character and then a three-letter suffix at the end of the filename. The software program generally assigns file extensions. Excel workbook files are assigned the extension .XLS by default.
It's not necessary to type the file extension when you're naming a file. Excel looks at the file type that's selected and adds the correct extension.
Make sure that you don't change the file extension. Although you might think that using a file extension like .BUD to identify all your budget files is a good idea, you'll have a hard time finding those files later.
The extension on a filename is a road map for Windows. When you open a file, Windows uses the file extension to determine which program that file belongs to. Table 3.2 shows the most common file extensions used by Excel and explains a bit about them.
What It Means
Microsoft Excel workbook
Microsoft Excel template
HTM or HTML
Microsoft Excel add-in
Microsoft Excel workspace