I can't quite figure out for certain what you're asking but I'll make a couple guesses.
Standard house current arrives at your home using a 60CPS (cycles per second, also called hertz, named after Heinrich Hertz.) There are impurities in the electrical current, minor fluctuation's called spikes that can sometimes appear as other frequencies but the primary power source is delivered using the 60hz voltage.
A single "wave" of the current can be observed by using an oscilloscope. Starting at the point where the voltage is zero, the voltage rises to a peak, then falls, passes through zero again and peaks in the opposite direction and finally returns to zero. This describes a cycle or sometimes it's called a "wave".
I hope this has answered your question.
An Electric Current :)
Gravity
That is called an electrical current, or just a current.
is called an electrical circuit
The time required for a single vibration (back and forth motion).
Diffusion current is current that is generated due to the vibration of electrons.
piezo electric principle
Yes, an electric current is the flow of charged particles.
DC current
If you mean molecular vibration than this is called "heat" and gives the object its current temperature.
All current is the passage of electric charges from one terminal to another through a conductor so there is no real difference in the type of current that flows in a 3 phase system compared to a single phase system.
A current.