What is the difference between a folder icon and a shortcut on the desktop?

Icons point directly to a program or other object, are inextricably linked with them and subject to the same changes. Any actions with them will lead to a change in the state of the object.
Desktop shortcuts are links to a program, file, or other object, represented by an icon. Manipulations with them have no effect on the object.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.