The best known are Apple's iPod products but they also tend to be the more expensive products. A "good" MP4 player is one that has the features that you are looking for and within a budget you can afford. It means doing some research before handing over cash to anyone.
Things to consider are:
No, they are not quite the same. 'MP4 player' is the marketing name for an MP3 player that can play a greater range of formats than an MP3 player, they have a screen for video, usually in AMV format. The name is misleading as they rarely play true MPEG-4 '.mp4' format files.
iPod and mp4 have the same quality. mp4s are better than mp3s. iPod and Mp4
They are the same things but I have an iPod Touch and an mp3 player but I use the iPod much more because you can have APPS on it :)
Basically, MP3 is an audio file format, MP4 is a video file format. You can download movies onto a MP4 player and watch them back.
No that's why it's called an MP3 player...
Unfortunately, there isn't a way of converting it unless you buy a MP4.
An MP3 is one of the most common sound file formats currently used in digital music devices. Similarly, an MP4 is a video file format. An MP4 player generally supports both MP3 and MP4 formats, meaning that it can play both music and video. An MP3 player, unless otherwise stated by the manufacturer of the device, generally does not support the MP4 format or other video formats.
nothing
Depends what mp4 player do you have?
You can by downloading an app on your PC/laptop then plugging your mp4 into it and downloading on your mp4. (it wont work if you have an mp3 it must be mp4)
nothing thats it
An MP4 to MP3 converts files that are in the MP4 format to MP3 format. This can be helpful when a device cannot play an MP4 file and must be converted to be played.
No you can't. mp3 players are meant to play songs (mp3 format) not videos (mp4 format). You can put them in, but you will not be able to play them on your mp3 player.