In our daily life, robots are often found to do work that is too dangerous, boring, difficult, or dirty. And we often see kids play with toy robots.

But what exactly is a robot? There are some important characteristics (特征)that a robot must have. These characteristics might help you to decide what is and what is not a robot. It will also help you to decide what you will need to build into a machine before it can be considered as a robot. A robot has these important characteristics:

Sensing First of all, your robot would have to be able to sense the environment around it. Give your robot sensors(传感器): light sensors (eyes), touch sensors (hands), chemical sensors (nose), hearing sensors(ears)and taste sensors(tongue).

Movement A robot needs to be able to move around its environment. It can move on wheels, walk on legs or be driven by small engines(发动机). A robot can move either the whole body or just parts of it.

Energy A robot needs to be able to power itself. Some robots might power itself with sunlight; some might with electricity, while others with the battery(电池). The way your robot gets its energy will depend on what your robot needs to do.