Nowadays science and technology have become important in our daily life, especially in the 21st century. Through science and technology, we have improved our standard of living in many ways. For example, medicine, communications, transportations all these have become more advanced and convenient. First of all, science and technology have played a role in the industry, and we can find that robots are now replacing humans in many factories although robots are more accurate and efficient, and it is more expensive. Moreover, medical science has always improved, and a lot of diseases has discovered new treatments and vaccines. By using smartphones, we can keep in touch with our friends or families easier via Facebook, Instagram etc. The current technology has made communication very simple to use, and it is no longer necessary for us to send a letter and need to wait for a week. The network and technology are connected, we can watch videos or movies from the internet, listens to new songs, read novels, and all these are free only with wifi. Once the technology has developed, the use of the network will be wider. Besides, technology has been used to develop all vehicles such as hybrids cars that can charge by electrics. We also have technology of 3D printer that can make models, and we only have to input the data inside the software, and it can automatically create the model, for example, we can print out a 3D prosthetic limb to help peoples that have lost their arm, hand, leg or foot through accident can perform ordinary activities.