Well, let me put it this way: if you follow that big black (mostly black, but it comes in flavors) cable from the back of your machine long enough, you’ll be stuck sooner or later right in front of a wall.
Do not despair but remove the cable that seemingly grows out of this wall.
You are still with me?
Perfect!
Now, look at the place where the cable had been before you removed it.
Depending what country you live in, you’ll find a couple of small holes, sittin in a white (your’s maybe grey, does not matter: beneath the dust it is white) piece of plastic.
Ok, now take two pieces of thick wire, one in each hand, and put each one in one of the holes!
You will feel a short sensation, maybe even you will think something has hit you.
THAT comes from the electricity that sits inside these holes.
You know now what electricity is - not only a word, but something weird: you can not see it, you can not smell it (normally), but you simply KNOW it is there.
Now, making of electricity is a little more complex then finding out if it really is there. Would be too much for the limited space in this forum to describe properly.
But it is like with most things: even komplex matters are described very easily, all you need is the will to get to the base of things.