How do electronics devices work?

Question

I am wondering how electronics work. Specifically portable, digital electronics with graphical user interfaces like cell phones, iPods, PSP's and other devices.

How is the interface created for the device?
When you press a button or key, how does it know what to do? For example, when you press a button on a cell phone, how does it know what letter or number to show on the screen, especially when the functions of buttons change for different applications?
Please be very detailed.

Answer 1

This is a good question, but beyond the scope of this forum.
I suggest you go to your local library and check some basic books on how electronics devices work.

If going to the library is not an option, Wikipedia offers lots of basic articles.

In very simple terms, electronic devices have a computer inside.
Buttons on a cell phone act like input devices (say, a keyboard on a computer). The same way your PC interacts with your keyboard and mouse an electronic device interacts with control buttons.