There is a question that how much artificial intelligence can become close to the human brain. So, the question of what the differences between humans and machines are arises. Sometimes, I think to myself the difference is that we can understand the concept of infinity but machines cannot. Our thoughts can walk at the area of infinity. That is, roughly speaking, we can say the distance between elements of a Cauchy sequence is zero at infinity but not zero everywhere. However, in computers, because of the lack of precision, the distance becomes zero when the distance becomes smaller than the machine epsilon, and even if we would have a computer with infinite precesion, then the distances would never become zero. In another way, there is a difference between finiteness and boundedness. For example, tan(x) is finite between -pi/2<x<pi/2 but not bounded. However, machines cannot realize this difference.