What is the process of summarizing data found on multiple worksheets on one worksheet is called what?

If you have data on Sheet1 and Sheet2 that you want to display on Sheet3, do the following.

Assume you want to show B23 from both Sheet1 and Sheet2 on Sheet3. Go to Sheet3 to the cells where you want to display the data and enter the formulas in two different cells on Sheet3: =Sheet1!B23 and =Sheet2!B23

To reference another worksheet in the same workbook, preface the formula with the Sheet name (located on the tab below the worksheet -- you can change this name by right-clicking on the tab and changing name) and an exclamation point (!). In the example above =B23 would reference cell B23 on the same worksheet, but =Sheet!B23 will reference the cell B23 on Sheet1.