As trivial as it may seem to install applications, there are a number of items to be aware of if you're a new Mac user. This quick tutorial will give you a run down on how the installation process works and the common types of install files you can encounter.

One important note before we start this tutorial is that all applications will be installed into the Applications folder - like Program Files on Windows. If you click on the thumbnail below you will see a screenshot of where you can find the Applications folder.

DMG (Macintosh OS X Disk Copy Disk Image File)
Almost every application you will download will be contained in .dmg files. DMG files are Mac's version of disk images and will contain all the necessary files to install a given application. If you think disk images mean you have to burn them, rest assured Macs can mount these images natively.To install an application from a .dmg file, you just have to double-click the file. Normally double-clicking a .dmg file will invoke the file to be mounted like when you insert a USB storage device. Depending on the application, you may be presented by an EULA (End User Licensing Agreement) that you have to accept, like for Firefox, before you are presented with the contents of the .dmg file.

Now all you have to do is drag the application icon into your Applications folder and it is installed.

PKG (Mac OS X Installer Package)
Another common type of file you will encounter are .pkg files. PKG files are installer files on a Mac and involve more user interaction, it is akin to a setup wizard - you can see this in the screenshots below when installing a free video-player called MPlayer.

To install applications utilising .pkg files, you just have to follow the on-screen prompts and the application will be automatically installed within the Applications folder.

SITX and ZIP
At times applications may also come pre-packaged in .sitx and .zip files. These are simply archival files which, when extracted, should contain either a .pkg or .app file (Application package). Macs come with native ZIP file support and do not require further applications to extract its contents, double-clicking the file will extract its contents. SITX (StuffIt X Archive) files on the other hand require the application StuffIt Standard Edition before the file contents can be extracted. Once the application files have been extracted, like for DMG files, you just have to drag the application file into the Applications folder.

On some rare cases during application installation, normally with .pkg files, you maybe prompted to supply your user account password. This means your Mac is asking for your permission to install some elements of the application with elevated privileges - this is normal but be wary to be installing an application from a trusted source.

If I have missed anything or you would like further clarification on a topic, please feel free to leave your comments below or email us at edit@applesource.com.au.