They are photo frames that run on mains electricity or batteries (or both) and display digital photographs either from the memory card from the digital camera or direct transfer from a pc.
They are of varying quality and this is not always reflected by the price.
I have done a lot of research into them and unless you get a higher resolution screen at least 800x600 you will probably be disappointed with the results.
If people send you a jpg through email you can connect the photo frame to your PC if it (the frame) has a USB connection and add them.
Some have internal memory. Some also accept various camera cards.
i got a 5.6 inch screen datawrite one
bluetooth
speakers built in +
bluetooth
plays mp3 music and divx too
usb inputs
can play divx movies from flashdrive
40 quid from ukdvdr , was on special till 14th december dunno price now.
its good and im happy with it especially at that price.