Types of current AC/DC

[Saturation]

Ok, i know that there is only one type of AC----> alternating current, which flows backwards and forwards, which is generated from generators.

But for DC i know that there's steady DC, Varying DC. Varying DC comes from AC which has been rectified right?

Can someone enlighten me about the forms of DC please and give some examples from where they are generated?
Thank you! :mrgreen:

 

[kkw]

are u in coordinated or separate science?? both require different levels of understanding

 

[Saturation]

Well it's for Physics CIE 0625