Spreadsheets can be saved in the following three ways.
From the menu bar
Click File and then select Save (or Save All or Save As).
From the toolbar
Click on the Save button
on the Function bar. If the file has been saved and no subsequent changes have been made, this button is grayed-out and unselectable.
From the keyboard
Use the key combination Control+S.
If the spreadsheet has not been saved previously, then each of these actions will open the Save As dialog. Here you can specify the spreadsheet name and the location in which to save it.
|| If the spreadsheet has been previously saved, then saving will overwrite the existing copy without opening the Save As dialog. If you want to save the spreadsheet in a different location or with a different name, then select File > Save As.