They are two different applications. Oracle is a database and Excel is a spreadsheet. So it will depend on what it is you are intending to do that determines which application you would use. Spreadsheets are for numerical analysis and manipulation. Databases are for dealing with lists of data and processing them. There are things both can do.
how to create a excel sheet
Pfa the excel sheet
Add a sheet
They are the same thing, excel is Microsoft's spreadsheet programme.
Calculating DSCR in Excel sheet
Select the sheet.
A spread sheet
scale to fit
scale to fit
17,179,869,184 cells in one excel
I believe chart sheet.
Normally when you open Excel there are 3 sheets open. They are Sheet1, Sheet2 and Sheet3. Sometimes you will want to give more meaningful names to those sheets. By right clicking on the sheet tab and clicking the Rename option or by double clicking, you can rename a sheet. So you could have many sheets with names on them that are meaningful to what you are doing, which is what we mean by naming sheets.