Installing Applications
Installing applications often seems to be a little different than in Windows XP. I read somewhere that it is simple: just drap the application into your Applications folder. However I tried that with a .dmg file and it just sat there, useless.
First, the Applications folder, which is under your home directory (but there is also a shortcut to it in the Places section of the Finder) is like the Program Files folder in your C: drive in Windows and is where applications like to be placed.
So far I have found 3 ways that applications are deployed
1. As an application (.app) in a disk image (.dmg) file or sometimes in an archive (.zip). This seems to be the most common. If you get a .dmg file, double click it and it will open up, often showing something like this:
There may or may not be notes files at the bottom. The key part is the icon for the application which you can drag over to the Applications folder in the window and that will put it in the right place. At that point you can run the application. Very simple.
If the application comes in an archive file, you will have to use the Finder to drag it to the Applications folder.
2. As an installer package either in a disk image (.dmg) or in an archive (.zip or similar). This is the most similar to how applications are installed in Windows using the Windows (or similar) installer.
Double click on the .mpkg file and follow the instructions (often including a license you must agree to just like in Windows) to install the application.
Whenever you get something in a disk image (.dmg) and open that image, you are mounting the disk image like a pseudo disk and you get a disk-like icon on your desktop.
When you are done with the installation you can drag this to the Trash to clean up the clutter on your desktop. The disk image file will still be in your Downloads folder (or where ever you store downloads) so you will probably want to clean out that folder, too, every once in a while.
3. Actual application (.app) files. I don’t think this is too common but again, you would use the Finder to drag it to the Applications folder.