A Workbook is just a collection of worksheets. If you look near the bottom of the Excel screen you will see a group of worksheet tabs.

These tabs are labelled with the names of worksheets belonging to the current workbook. You can easily switch between worksheets by left clicking on the tab of the worksheet that you want to view. The name of the worksheet that you are presently working with will be in bold type, and the tab colour will be white. In the image shown here, Sheet1 is the worksheet that is currently being used.

You can also use the worksheet navigation buttons just to the left of the worksheet tabs to switch between worksheets. The left pointing triangle moves to the next worksheet. The right pointing triangle moves to the preceding sheet. The left pointing triangle with a vertical line moves to the first worksheet in the workbook, and the right pointing triangle with a vertical line switches to the last worksheet in the workbook.

To quickly switch between workbooks using the keyboard, press the Ctrl +Page Up and Ctrl + Page Down keys.