AC & Diode: What Happens When Wave Enters?

[sanado]

Hey guys, just thought id clarify what happens when an AC current passes through a diode. Say for instance the wave featured in the link below entered a diode, what would it look like once it leaves the diode?

http://www.pcguide.com/ref/power/ext/z_ac.gif

 

[Chi Meson]

In the simplest sense, what do diodes do?

And also, in the simplest sense, what does the current in an ac circuit do?

Put these together and say what would happen if a diode is put into an ac circuit.

 

[Redbelly98]

We need either a more specific description of a circuit containing a diode, or perhaps a better phrased question.

If the attached waveform (a voltage) is applied across the diode leads, then that is the voltage across the diode leads. Voltages don't "enter" and "leave" a diode.

Or are we wondering about the current through the diode, given the voltage waveform applied across the leads?