Desktop Icon Research, by DevJ

Desktop icons are most typically used in 16x16, 32x32, 48x48, 96x90, 128x128 or 256x256 pixel sizes. Using smaller sized icons will result in less clarity, smoothness and definition. Typically, 128x128 and 256x256 pixel sized icons are considered HD, or high resolution. 

Most of these higher sized icons will use 96dpi (dots per inch) or something in that vicinity. The use of different sizes most often is based on your screen's resolution, and graphics capabilities of both the machine and the operating system.

For web use, optimal size may vary - it just depends on how big you want the icon to be! Useful icons may include:

●	generic file folder (files/file storage)
●	hard disk (save action)
●	folder with a search icon on it (file search)
●	question mark (help)
●	a tool (settings)
●	chain (link)
●	house (home)
●	closed envelope (new mail)
●	open envelope (read mail)
●	box with an arrow (share)
●	heart (favorite)
●	star (favorite)
●	trash can (trash)
●	clock (time)
●	flag (marking items)
●	scissors (cut)
●	clipboard (copy)
●	glue (paste)
●	generic picture (photo)
●	movie reel (video)
●	generic contact card (contact)
●	key (lock)
●	scroll (text)
●	chat bubble (comment)
●	shopping cart (shop)
●	pencil (write)
●	eraser (erase)
●	outward arrows (larger size or full screen)
●	printer (print)
●	ascending bars (wireless strength)
●	generic power sign (power on/off)

Although these might be basic, they are vital to a users control environment. They are all things that a user will do on a regular basis, in almost every application or website. 

Also, social networking icons would be very helpful, especially in todays very social web environment. You could include all the basics, and any that you might uniquely use. 

●	Facebook
●	Twitter
●	Google+
●	Scribbble
●	GitHub
●	LinkedIn
●	Tumblr
●	Instagram
●	Pinterest
●	YouTube
●	Blogger
●	WordPress
●	app.net
and many more… depending on social services you use.

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Thanks so much for your time, it's really appreciated to us students!

Best, 
DevJ