He didn't approve of AC - alternating current.
Say you hook both wires to the bulb, and then you clip one to each side of a battery. What happens?
A negative charge means there is an excess of electrons there. Each electron is a little negative charged particle.
So - to go back to start - first we hook up one of the wires. Then we hook up the other, electrons start to flow.
Electrons and magnets are related.
You can turn that around.
If you move a magnet past a wire, at the instant the magnetic field moves across the wire,electrons try to flow.
Oh, you can also hold the magnet still and move the wire.
Back to the battery and the light bulb.
So we hooked up our wires, and the negative side had an overabundance of electrons, and the positive side had a bunch missing, so the electrons flowed through the filament to correct the imbalance.
And the magnetic field stayed active, unchanged, except at the moment of connect.
That's how Edison saw it.
He saw a world without a "grid" as we know it now, where the electricity was generated and consumed all in the same place.
Enter George Westinghouse.
Alternating current does transmit easily over long distances.
With AC it's like you hooked them up, and then reversed them, so the negative wire became positive, and then back, rapidly. 60 times s second in US.
And because of the magic of magnetism and wires, we can rejigger the electricity so it will travel over miles and miles of high line, and be tamed to work your clock radio.
Edison referred to execution by electric chair as "Sending a man to the Westing House."
So what has this got to do with us, here, today?
Or all of the above.
I had a ne'er-do-well shirttail hillbilly relative who had the first electric lights in Cass County, MO.
He took the generator and battery from a Model A Ford,
Are you ready for this?
It won't work well with our grid.
Solid state stuff (computers etc) all runs on DC low voltage anyway. That what wall warts are for.
What it is, is, a few people make lots and lots of money off the current system.
We have this grid. Electricity flows one way and money flows the other. A few powerhouses sit on the grid
We have a 36 volt farm chore cart, an old EZ-GO golf cart. About twelve or thirteen years ago I hung a solar panel on its roof, put some technical this-and-that in it, and we never plug it in.
6, 6-volt DC lead acid batteries.
No gasoline. Ever.
No oil changes. Ever.
No spark plugs. Ever.
It just works.
As a society, America is strikingly stupid.