Welcome. My name is ***** ***** would be glad to assist.
US power is not split phase, it is referenced as single phase also.
The 2 power sources are derived differently from the power stations generators.
The thing to understand is this:
In the US, there are 2 wires, that measured to ground or neutral will have 120 volts on them.
Then measured between those same 2, you will get 240 volts, which its the combination of the two.
Elsewhere in most of the rest of the world, you have 230 volts, which is derived form one single wire measured to ground or neutral.
The neutral, is an ungrounded conductor which carries the same current as the hot wires. It returns the current back to the originating transformer.
Power flows out on the hot, returns back on the neutral, so it essentially is a circle in the power supply.
The problem with US made appliances like dryers, ovens etc, is that the electronic circuit boards inside them for operating everything, are manufactured to operate off of 120 volts, not 230 or 240 volts.
Everything except motors and heating elements operate off ONE of the hot wires and the neutral, which measure 120 volts.
The motors and heating elements will operate off the 2 hot wires only which combine for 240 volts.
Other countries operating at 230 volts, do not have 120 volts to operate the remainder of the appliances.
So, if one connects a US appliance that operates on 240 volts to a power source of 230 volts in other countries, it will damage everything inside because the voltage is inadequate for them, it is too high.
Another item in them, is still motors, which in the US operate off 60 HZ frequency of the utility supply.
In most other countries with the 230 volts , they operate on 50 hz power.
So, motors will run at a different speed 20 percent high or lower depending which direction.
A 60 hz motor will run 20% slower on 50 hz, so that too can be a problem on some appliances.
Those are the differences, hope the explanation helps, let me know any questions.