Notes

Human Body acts like a resistor against a small current of AC (Alternating Current) or DC (Direct Current) , But
Sometimes the body resistance will go down at which the low voltage AC or DC can burn human.
Such conditions might include working with electronics with open palms or trying to change 12V (car and bike battery) on a rainy day
both of them can turn a slight shock into fatal event.
it's very clear, Both AC (the power from the wall outlet and etc) . and DC (the power from car or bike battery etc) voltage
can damage human body in many ways.

Effects of AC Voltage : This type of regularly reversed direction. This can cause human heart to shift its regular beating
pattern in a condition known as ventricular fibrillation (The most serious cardiac rhythm disturbance which cause Cardiac arrest)
if it happens, human heart muscles go out of whack in a way that causes blood to stop pumping, in this situation
even if the current is cut, human heart might not be able to find its proper rhythm, and person can die .

Effects of DC Voltage : This type of voltage is constantly on , And causes human body muscles to contract and seize up quickly
including your heart muscle. If body grabs an electrical device in conditions that cause the body to conduct DC voltage, hands could
became frozen, Unable to let go of the device, and heart could stop. if someone cuts the current quickly, though , Heart might begin to beat again.

Difference in Voltage uses over countries :
Over the years, the trend has been towards higher voltages. Although lower voltages are safer, that is less of a concern these days with strict codes and regulations.

In the United States, 2-wire 120 volt service has been replaced with 3-wire 120/240 voltages or with three phase 120/208 voltages. In Europe many supplies were changed from 3 phase 4 wire at 127/220 volt to 3 phase 4 wire at 220/380 volt. In the UK most early supplies were 3 wire DC at 120 volts, but that was later changed to 240 volts.

Electric shock from either AC or DC can cause burn on human body as the current dissipates across body's natural resistance
which includes skin
How to avoid Electric shock for AC and DC current :
1- Don't work with electrical items in wet environment.
2-always take protective measures.
3-Never touch any of the electric or electronic items, components or circuits when connected to the current.
4-Always disconnect the electric as part of the safety measure .