Beginner question: analog  and digital

I am total new in this.
Can someone explain the difference between analog and digital current??
When should I use the analog or digital in/out?

Hi yeager, the short answer is: digital output turns something on or off, there is nothing in between. Analog output on the arduino has 256 levels between 0 and 5 volts that can be used to change the apparent voltage being fed to a device like a lamp

You can read more about this here: http://www.csulb.edu/~bevans2/arduino_notebook_v6beta.pdf

Also note that the analog outputs arent true analog, they are digital which are pulsed extremely quickly.
For some things it doesnt matter, others it does.

The analog outputs are usually used for things like making leds fade and servos.
Digital outputs are for switching things, communicating with other IC’s and most other things.