carlosthejackle2001 said:
I don't know, I'd just like to know a bit more than it's a power source for plugging your tv into n stuff.
The power companies generate via large generators that are powered by usually steam from coal burning, or nuclear or via turbine from wind or water.
The voltages are stepped up to many Mega Volts for long distance travel, when they get to supstations, they are stepped back down for distribution.
They are transmitted as 3-phase.
You can have 110-120, 220-240, even 480 delivered. If you are a factory, you might want 3-phase 480V for running large motors etc... If you are a household, maybe you just need single phase 120V and 220 for stoves, washer/dryer etc... The consumer markets in US have developed around 110-120V and 220/240V for larger items. Other voltages are available.
Depending on what civilized country you live in, the frequency is regulated to 50 or 60 Hz. and it is good to something like +/- .001 Hz. So, it is regulated and you can use it for CRUDE clocks if you need it.
Due to all the horribly non-linear loads on power lines and effects like lightning, there are very nasty transient events that occur to look out for.
When designing, one must take into account low-line and high-line conditions and transient protection. Nearby lightning strikes can cause thousands of volts to appear briefly on the line.
Complete industries exist for the sake of circuit protection and overload protection from events on the mains power.