Hi, received my 1st mac ever today. So far, so good, I like it much better than my old Dell. Set up was easy, and I even upgraded the HD, and all online software updates. Couple questions: I downloaded google chrome and skype, and I noticed that both applications generate a main application icon (the one you click to start the program), along with an icon that lands on the desktop that looks like an HDD or something - what is this for? Do I need it to run the program? Is it trash? With chrome, I also see 3 other files, named google chrome alias, alias (2) and alias (3) all three use the same HDD looking icon - do I need these? Thanks!