Portable entertainment devices such as MP3 or DVD players which allow people to listen to music or watch films are now commonplace. What do you think are the main advantages and disadvantages of this development?

Nowadays, electronic products such as MP3 or DVD players become to be part of human's life. People uses these techniques everywhere as its compact and easy to carry because they are smaller than a CD player so it fits in you pocket. For example we can carry our MP3 players during jogging or travelling. Besides that, it has lots of applications such as calendar, clock, or even games, also you can watch any videos. On the other hand, these portable devices have some disadvantages, as the screens are very small, and the sound quality won't be that much clear. As well as it can cause hear damages because of using headphones. However, MP3 or DVD players play a great role in humans life, as they are movable techniques and easy to use.