In Mac OS X the applications are often ‘packages’: the application itself and all its various support files all bound up together in one special folder, with its own icon.
Classic, Carbon and Cocoa may explain why some features work in some software, but not in others.
Command Tab lets you switch easily between different running applications.
Apple computers have brought innovation to computer users, making popular items such as the mouse, the laser printer and the graphical user interface.
How to set up a new User in early versions of Mac OS X.
How to install software from a .dmg (disk image) file.