Simplify the following text for a Grade 5 native English-speaking person.
Original: Even for a 3-axis CNC milling machine using the same control system as a robot arm , it is the arm which is almost always called a robot , while the CNC machine is usually just a machine . Having eyes can also make a difference in whether a machine is called a robot , since humans instinctively connect eyes with sentience .
Simplified: A robot is a machine or a computer program which seems to have a life of its own .