What is a Workbook?

 * In Microsoft Excel, a workbook is the file in which you work and store your data. Because each workbook can contain many sheets, you can organize various kinds of related information in a single file. As you see in the above figure, the Workbook is named Book1 (look at the Title bar). Book1 is the first thing you see when you start Excel XP. Book1 is an Excel-given name. If you do some work, you have to name it differently and save it if you want to be able to retrieve it in the future.

 This Workbook has three sheets: Sheet1, Sheet2, and Sheet3. Yow will learn later in this manual how to change the number of worksheets in a workbook. There is no limit to this number; the only limitation is imposed by available memory. 

         * The worksheet, also called a spreadsheet, is the primary document you use in Microsoft Excel to store, analyze, and work with data. The easiest thing you do to understand what a worksheet is to magine it as a page in a book. A worksheet consists of cells organized into columns and rows.The maximum number of columns in a worksheet is 256 columns, while  the  maximum  number  of  rows  is  65,536  rows.  A  worksheet  is  always  part  of  a workbook.

What is a Worksheet?

     The worksheet , also called a spreadsheet, is the primary document you use in Microsoft Excel to store, analyze, and work with data . The easiest thing you do to understand what a worksheet is to imagine it as a page in a book.  A worksheet consists of cells organized into columns and rows  . The maximum number of columns in a worksheet is 256 columns,while  the  maximum  number  of  rows  is  65,536  rows.  A  worksheet  is  always  part  of a workbook.  You can enter and edit data on several worksheets simultaneously and perform alculations   based on data from multiple worksheets. When you create a chart, you can place the chart on the worksheet with its related data or on a separate chart sheet. The names of the sheets appear on tabs at the bottom of the workbook window. To move from sheet to sheet, click the sheet tabs. The name of the active sheet is bold. In the figure above, Sheet1 is the active sheet.

       What is a Cell?

Each worksheet is comprised of tabular girded cells. A cell is the basic unit in theworksheet that can hold data, and is the result of a column intersecting a row  (see the previous figure).

 

  

         What is a Reference?

A reference identifies a cell or a range of cells on a worksheet and tells Microsoft Excel where to look for the values or data you want to use in a formula. With references, you can use data contained in different parts of a worksheet in one formula or use the value from one cell in several formulas. You can also refer to cells on other sheets in the same workbook, to other workbooks, and to data in other programs. References to cells in other workbooks are called   external references. References to data in other programs are called remote references. 

 

By default, Microsoft Excel uses the   A1 reference style, which labels columns with letters (Athrough IV, for a total of 256 columns) and labels rows with numbers (1 through 65536). To refer to a cell, enter the column letter followed by the row number.  For example, D50 refers to the cell at the intersection of column D and row 50   . To refer to a range of cells, enter the reference for the cell in the upper-left corner of the range, a colon (:), and then the reference to the cell in the lower-right corner of the range. The following are examples of references. 
 

Refer to	Reference
The range of cells in column A and rows 10 through 20	A10:A20
The range of cells in row 15 and columns B through E	B15:E15
All cells in row 5	5:5
All cells in rows 5 through 10	5:10
The cell in column A and row 10	A10