The typical installation will install the program into the app folder of the installing user and requires no special permissions. This is the recommended install for a single user machine.
If you are installing to a shared machine such as a terminal server, you may want to perform a shared install. A shared install requires the install be performed by a userid with Administrator permissions.
You should not choose Shared Install if you are using a Personal license. Shared install is meant for use only by Team and Enterprise licenses.