Software Considerations in a Multiuser System
Mac OS X is a multiuser system. When it comes to installing software, this seemingly small detail really matters. For one thing, not all users might have the same privileges on the system. When you set up user accounts, as will be explained in Hour 15, "Sharing Your System: Multiple Users," you have the option to prevent others from modifying the system in any way. That includes installing additional software.
Also, when you install applications, keep in mind that other users don't necessarily have access to your home directory. If you install a large application in your home directory, you might be the only person who can use it, which could lead to other users installing copies of this same application on the same machine. To best utilize disk space and resource sharing, major applications should be installed in the system's Applications folder or in a subdirectory of Applications, rather than inside your home directory.
One other issue: Be sure to read your software license agreements regarding operation by multiple users. If an application is licensed for only a single user (rather than a single computer), it should not be placed in the Applications folder where any Mac OS X user can have access.