Unwanted Desktop icons

Hi,

Please excuse this if this is a dumb question with a simple fix, however...

After installing Firefox and Skype, an icon appears on the desktop under my Mac HD icon whenever I open these applications. I can't quite understand why these icons persist when others I've downloaded (e.g. Onyx) do not produce an icon when I open them (although, of course, it has an icon in the dock).

How can I have Firefox and Skype exist simply in my dock, without these icons appearing and cluttering my desktop every time I use them?

Many thanks.

You have not installed them yet. You're still using the dmg to launch them.

After you open the dmg, you need to drag the icon for the app into your Applications folder. Once you've done this, you can then drag both, that icon that looks like a hard drive and then the dmg to the trash.

Many thanks, bobtomay! Now I get it!