# Get Familiar with Spreadsheet Structure in Microsoft Excel

Microsoft Excel is all about data and spreadsheets. Each cell in a spreadsheet has a unique cell address consisting of its column letter and row number.

Each cell must have its own unique address so that you can refer to it when you create a formula. For example, suppose that you want to sum (add) the values in cells B3 and B4. You can write a formula like this: =B3+B4.

When you copy a formula that refers to cells by their addresses, the references to those cells automatically adjust to take into account the new position. For example, suppose that you have the formula =A1+1 in cell A2. If you copy that formula into cell B2, the copy of the formula reads =B1+1.

A range is a group of one or more cells. You refer to a range by the address of the upper leftmost cell in the range, followed by a colon, and then followed by the lower rightmost cell in the range. For example, the range consisting of cells A1, A2, B1, and B2 is written as A1:B2.

Technically, a single cell can be a range, but usually it isn’t called a range.