What is xls

The XLS file type is primarily associated with spreadsheets created in Excel by Microsoft Corporation, the most widely used spreadsheet program. Program: EXCEL.EXE stores data in a table with rows and columns. Table cells can contain manually entered data or the results computed from the data of other cells. Excel is used to create charts and graphs.


Formulas are entries that have equations that calculate the value to display based on other cells in the spreadsheet. In the below example the formula is in the column Total Price. The formula typed into cell D2 to find the total price for apples is:


It’s important to remember to type in the cell reference instead of the constants. If I had typed in 1.99*2.4, the answer would work for that example, but I couldn’t copy and paste the formula for the rest of the produce. Also if the price per pound changed, or the weight, I would have to audit those columns AND the calculated column. BEST PRACTICE is to use cell reference.

Remember all formulas must start with an equal sign =

Data Types



Constants are entries that have a fixed value. If you ask someone their birthday, they would answer a specific date. People may have different answers, but it is a fixed value for each person.

Data Types

In the example above, the constants are in the columns Price Per Pound and Weight:

  • 1.99, 1.49, 6.99, 5.99
  • 2.4, 1.5, 125, 2
Constants can refer to dollars, dates, percentages, and other items referring to a value that can be used in a calculation.


Labels are text entries without a value associated to them. Labels are used to identity what we are talking about; used for clarification for end user.

Excel Lables

In the first example above, the labels are:

  • Produce
  • Price Per Pound
  • Weight
  • Total Price
  • Apples, Bananas, Grapes, Cherries
Labels are used to help identify what we are talking about.

Excel Data Types

In an excel spreadsheet there are three basic types of data that can be entered:

  • Constants – a number, a constant value
  • Labels – text with no numerical value
  • Formulas – a mathematical equation used to to calculate; all formulas begin with =
Data Type Description Example
Constants Any number 23 or 10.5 or -75
Labels Name or Days or Month Anything that is just text
Formula Math Equation =10/2 or =match(A2,$C:$D,0)