One of the very first things I looked up when I first got my Macbook was how to install applications on OS X. Installing applications is incredibly easy for most users, but for new users it can sometimes be confusing. There are several different ways that applications on the Mac can be installed. We’ll discuss the main methods below.
Most Mac applications are downloaded as a .dmg file. The .dmg file is a disk image that contains the compressed application files. After downloading the dmg file, Safari will automatically open and mount the file in the finder and on your desktop unless you have changed the default preferences. If you are using another browser, just double click the file and the disk image will mount on your system.
From this point, application installation can vary a little. Some applications, like Adium, provide you with a pointer (alias) to the applications folder in the installation window. Just drag the application icon and drop it on the applications folder alias. The application will now be installed to your applications folder.



