OK,
2nd go, well fed up, as I misjudged how long it had taken me to reply, and, as I was typing into the site, it logged me out, & I lost the blinking lot!
Not happy.
This timeout is a bit excessive, also no spell checker, no ability to edit posts, this forum software is really in the dark ages!
Right, I’ll try again.
UK, 230V 50 Hz ac.
US, 110V 60 Hz ac.
There are other weird & wonderful supply types in the US, but at a receptacle for general use then the above would in general be true.
There is no large scale dc distribution any more.
This may make a comeback, and is, in the UK, but, I suspect that this will have some serious issues, because I have already come across so called electricians that can’t cope with the different challenges with ELC & dc!
IT equipment tends to run internally @ 3.3/5/9/12/15/24 V dc.
The Lenovo laptop I am typing this on has a 20V dc input voltage, i.e. the output of the PSU, which I strongly suspect contains a Switched Mode Power Supply.
The allowable inputs to this are 100-240V ac 50/60Hz.
Most wall wart chargers have similar allowable inputs, including Apple.
Now as far as motors go a motor designed to run @ 50Hz will run a little faster @ 60Hz, but this is nothing to worry about.
Much modern CE marked equipment has a universal input voltage of 100-240 (250) V 50/60 Hz.
This will be on the equipment rating plate with the CE marking, in which case you will be fine.
As far as hair dryers & straighteners go, I know that the females of the species in my household are very attached to their specific devices. IF, they have “allowable” input voltages then you will be fine, else, don’t bother. Me I’m not so fussy, I use anything available to dry my mane!
FS, if you want any more help, please give me a shout.