Human beings and robots are made up of the same basic components.  The computer element that a robot possesses distinguishes it from other machines.  Although a robot is difficult to define, this article will describe the characteristics of a robot or robotic system.

• A typical robot has a movable physical structure, a motor of some sort, a sensor system, a power supply and a computer "brain" that controls all of these elements.
• Robots spin wheels and pivot jointed segments with some sort of actuator. Some robots use electric motors and solenoids as actuators; some use a hydraulic system; and some use a pneumatic system (a system driven by compressed gases). Robots may use all these actuator types.
• A robot needs a power source to drive these actuators.
• Hydraulic robots also need a pump to pressurize the hydraulic fluid, and pneumatic robots need an air compressor or compressed air tanks.
• To move a hydraulic leg, for example, the robot's controller would open the valve leading from the fluid pump to a piston cylinder attached to that leg.  Typically, in order to move their segments in two directions, robots use pistons that can push both ways.
• To move the robot, the computer switches on all the necessary motors and valves. Most robots are reprogrammable -- to change the robot's behavior, you simply write a new program to its computer.
• A standard design uses slotted wheels attached to the robot's joints.
• These are the basic nuts and bolts of robotics. Roboticists can combine these elements in an infinite number of ways to create robots of unlimited complexity.
• The term robot comes from the Czech word robota, generally translated as "forced labor."
• The most common manufacturing robot is the robotic arm. A typical robotic arm is made up of seven metal segments, joined by six joints.
• An industrial robot with six joints closely resembles a human arm -- it has the equivalent of a shoulder, an elbow and a wrist.
• The robotic arm's job is to move an end effector from place to place.
• You can outfit robotic arms with all sorts of end effectors, which are suited to a particular application
• Robotic hands often have built-in pressure sensors that tell the computer how hard the robot is gripping a particular object. This keeps the robot from dropping or breaking whatever it's carrying. Other end effectors include blowtorches, drills and spray painters.
• Industrial robots are designed to do exactly the same thing, in a controlled environment, over and over again.
• Most industrial robots work in auto assembly lines, putting cars together.
• Robots can do a lot of this work more efficiently than human beings because they are so precise.
• Robotic arms are relatively easy to build and program because they only operate within a confined area.