The standard user of Microsoft Excel is often staying at a very basic level, inputting data in cells, performing basic operations like sums and averages, or just adding two or more cells using the +sign. However, Excel is a very powerful analytical tool that boasts functionalities to slice and dice large data tables according to the specific information requirements that managers and management accountants might have.
In the spreadsheet skills series by CIMA, there is a very comprehensive explanation on PivotTables for the first-time user. Although this particular post is from 2009 (and therefore does not include additional functions introduced with Excel 2010 and 2013), it provides a good introduction to what PivotTables are all about.