This chapter introduced Excel, and covered Excel's screen and the concept of workbooks and worksheets. The workbook documents contain your worksheets, and your worksheets hold data, such as numbers and labels. As you see throughout this part of the book, Excel supports a tremendous number of formatting options so that you can turn your numeric data into eye-catching, appealing output.
Although Excel works best with numeric data, Excel accepts text (called labels), date, and time values as well. Excel is extremely lenient about how you type dates and times but immediately converts such values into a special internal number. This internal number enables you to calculate with dates when you need to determine the number of days between two dates or when you need to add a fixed number of days to a date to arrive at an ending date, such as a due date.