If you click Show Details, you'll see all the available update, their version number, and the size of the update. A circle with a triangle inside next to the update means that your computer has to be restarted to completely install the update.
Click on each update to see the release notes for it in the window below. Click the checkbox next to each update that you want to install.
When you've made your selections, click "Install Items." You may be asked to enter your computer's password to proceed with the update, depending on how your computer is configured.
