first make your icon in paint then save as an ordinary file (.jpg) then use the online tool , favico maker and upload your image. The online tool will make it an icon file then it gives you the option to download it
Give it a .ico file extension example myicon.ico
An icon is a logo for a program
You can't turn a folder into a file. You can, however, make a folder look like a file by changing its icon (for instance, to the icon for a text document or Excel spreadsheet). You could also delete or move a folder and make a file with the same name, which might make it look like it had been turned into a file.
"ico" is a common extension for an icon. An icon is the image you see in a file browser or on your desktop. That icon will represent a file.
An icon.
.ico
You can make math worksheets printable by savig the file and then clicking the little icon that shows a printer. The other option is to use the File menu and select the print opion.
An computer icon is collection of programs or futures that displays in a single file that display as icon
A widget is a screen graphic or icon. A file widget, also known as a shortcut, is an icon containing a link to a file. Clicking it causes the file to open.
shortcut
I don't understand--why would you want to change the application icon? It is just an icon of a folder labeled "Applications." What are you trying to do? If you want to replace icons for individual applications rather than the icon for the Applications folder and you are using a set of icons with an .icns extension you can right click on the application's icon, select Show Package Contents from the menu, and open the Resources folder. In the Resources folder is the original applicationName.icns file. Move this original file somewhere safe (or better still make a copy of the application to experiment with) and then put your icon set in the Resources folder and rename it to whatever the original icon set was called. The application will then use your new icons.
The way I always do it is - right-click the icon and left-click properties. In the dialogue box that opens, there is a tab to change the icon. Remember to click Apply - then OK.
If it is an mp3 file (the most common type for downloaded music) you can play it in iTunes or Quicktime - you can drag the song file's icon onto the iTunes icon in the dock to load it. Try double clicking on the song file's icon and see what it opens in.