Excel 2007 spreadsheet
The spreadsheet is divided into alphabetical columns and numbered rows. The intersection of a column and a row is a cell. A cell can be identified by its cell reference composed of the column letter followed by the row number e.g. C2.
The active cell is the cell of the spreadsheet current selected. It can be identified by the black border around it, or by its cell reference in the Name Box. The column and row headers appear highlighted when a cell or range is selected to help the user identify the selected area.
When selecting more than one cell, this is known as a cell range. If you selected cell B2 to cell D7 it can be identified by its lilac colour and would be written B2:D7. The active cell remains white.
There are 16,384 columns in a spreadsheet ranging from A to Z and then AA to AZ, BA to BZ and so on. There are 1,048,576 rows in a spreadsheet. I don't think you will be needing extra cells anytime soon.