Nowadays, smart phone plays an important role in the human's life. In the 21st century, it's unlikely that any peple in the world doesn't own a smart phone, or even a mobile phone. Thanks for the development of technology, we can contact with everyone in everywhere with just a smart phone. Not only make a phone call likes 50 years ago when the first telephone was appeared, but also do everything. You can watch videos, find news, take a picture, make video calls,... by using amazing apps. Fistly, smrat phone is used mainly to communicate. You can use it to make a phone call, send and receive a message whereare how long distance. In addition, it can be used for entertaintment. Imagine that you are feeling tired, bored and anxiety, what do you need to reduce stress? Of course, you can listen to music, watch a movie, sing a song,... with a smart phone, it's so great for people who is usually under's pressure in work or study. And the last but not least, mart phone like a searching information device as long as your phone have wifi as well as maps to look for places when you are lost. With such functions of smart phone, i think you should own ones if you have not.